Smartwatches / Compare

Amazfit T-Rex 3 Pro vs COROS APEX 4

A

Product A: Amazfit

T-Rex 3 Pro

86 of 150 known

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B

Product B: COROS

APEX 4

75 of 150 known

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Every value links to where we found it.

Only differences

AAmazfit T-Rex 3 Pro

BCOROS APEX 4

General

6 of 10 differ

Series

T-Rex1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Amazfit T-Rex family. The page compares it with the T-Rex 3, T-Rex Ultra 2 and T-Rex Dual Solar.

APEX1Maker product pagecoros.com/apex4/specsRead 15 October 2026COROS APEX line. The overview page lists APEX in 2018, APEX Pro in 2019, APEX 2 in 2022 and APEX 4 in October 2025.

Model numbersiMaker identifiers for this exact model and its listed variants. Excludes sibling models and other generations.

W2549GL5N, W2549GL1N, W2549GL2N, W2444OV1N, W2444OV5N1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026US store variant SKUs: W2549GL5N Tactical Black 44 mm, W2549GL1N Black Gold 44 mm, W2549GL2N Arctic Gold 44 mm, W2444OV1N Tactical Black 48 mm and W2444OV5N Black Gold 48 mm. The German store uses other SKUs.2Maker product pageus.amazfit.com/products/t-rex-3-pro.jsonRead 15 October 2026Store feed variant SKUs by colour and size.

WAPX4-BLK-42, WAPX4-WHT-42, WAPX4-BLK-46, WAPX4-WHT-46, W542, W5412Maker product pageshop.coros.com/products.jsonRead 15 October 2026US store feed SKUs WAPX4-BLK-42, WAPX4-WHT-42, WAPX4-BLK-46 and WAPX4-WHT-46 for the watch alone. The feed has no barcodes, so no GTIN is stored.14Regulatory filingfccid.co/fcc/2BBGF-W542Read 15 October 2026FCC model W542 is the 42 mm. W541 is the 46 mm.

GTIN / EAN

850071618594, 850071618679, 850071618631, 6972596109655, 6972596109549, 6972596109440, 6972596109280, 69725961093581Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026The US store lists 850071618594 for Tactical Black 48 mm, 850071618679 for Black Gold 44 mm and 850071618631 for Arctic Gold 44 mm. The German store EANs are on the German store feed.2Maker product pageus.amazfit.com/products/t-rex-3-pro.jsonRead 15 October 2026Store feed barcodes. Only three of the five options carry a barcode.5Maker product pagede.amazfit.com/products/t-rex-3-pro.jsonRead 15 October 2026German store feed EANs: 6972596109655 Tactical Black 44 mm, 6972596109549 Black Gold 44 mm, 6972596109440 Arctic Gold 44 mm, 6972596109280 Tactical Black 48 mm and 6972596109358 Black Gold 48 mm. These belong to the German store SKUs, so no variant row carries them.

Not available

AnnouncediThe maker's first announcement of this model. This is separate from first retail availability.

5 September 20257Press releasezepp.com/press-release/amazfit-t-rex-3-pro-smartwatch-launches-featuring-a-rugged-titanium-design-and-integrated-flashlightRead 15 October 2026Release dated 5 September 2025 as the new T-Rex 3 Pro.

15 October 20255Press releasecoros.com/stories/press-release/c/coros-announces-apex-4Read 15 October 2026Release dated 15 October 2025 in Irvine, California.

Status

Available1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Store lists all five options at 399.99 USD and the add to cart button is active.

Available1Maker product pagecoros.com/apex4/specsRead 15 October 2026The COROS US and EU stores list both sizes with a Buy now button.

PredecessoriThe model this one directly replaced, in the same line, tier and size, as the maker or a trusted review names it.

Not available

Not available

SuccessoriThe model that directly replaced this one, in the same line, tier and size. A revision such as a Slim or OLED model does not count when a next generation exists.

Not available

Not available

Launch price (US)iThe maker's US launch MSRP for the stated configuration, excluding tax. Current store prices and later discounts do not qualify.

$3992Maker product pageus.amazfit.com/products/t-rex-3-pro.jsonRead 15 October 2026Feed lists 399.99 USD for every option. The launch press release says 399.00 USD, which is the stored value.7Press releasezepp.com/press-release/amazfit-t-rex-3-pro-smartwatch-launches-featuring-a-rugged-titanium-design-and-integrated-flashlightRead 15 October 2026Available for 399.00 USD on Amazfit.com and Amazfit retail partners. The Amazfit store now lists 399.99 USD. Prices exclude sales tax.

$4295Press releasecoros.com/stories/press-release/c/coros-announces-apex-4Read 15 October 202642 mm 429 USD and 46 mm 479 USD. US prices exclude sales tax.

Launch price (EU)iThe maker's euro launch price for the stated configuration, including VAT as published. Current store prices and later discounts do not qualify.

€399.94Maker product pagede.amazfit.com/products/t-rex-3-proRead 15 October 2026Amazfit Germany lists 399.90 EUR including VAT for both sizes. This is the current store price and it matches the launch price reported by nextpit.11Spec databasenextpit.de/smartwatches/amazfit-t-rex-3-pro-48-mmRead 15 October 2026UVP 399.90 EUR and market start September 2025, listed for the 48 mm model. The 44 mm page lists the same UVP.

€4496Maker product pagecoros.com/de/buy/apex4Read 15 October 2026COROS Germany store: 449 EUR for the 42 mm and 499 EUR for the 46 mm, including VAT. The EU store feed published the German product on 2025-10-15 at the same prices. This is the same price as today, since no launch-day German price list was found.

MarketsiISO country or region codes where this exact model or variant is sold. A source page's language does not establish availability.

Not available

US, DE6Maker product pagecoros.com/de/buy/apex4Read 15 October 2026US store product page and the German store page both sell the watch.

ColoursiThe maker's own colour names

Tactical Black, Black Gold, Arctic Gold1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Spec table: 48 mm Tactical Black and Black Gold. 44 mm Arctic Gold and Black Gold. The store also sells Tactical Black in 44 mm.

Black, White1Maker product pagecoros.com/apex4/specsRead 15 October 2026The store sells white and black watch bodies, each with nylon or silicone straps in several strap colours. Stored are the body colours.2Maker product pageshop.coros.com/products.jsonRead 15 October 2026Store option WATCH BODY COLOR: White, Black.

Segment

Outdoor1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Amazfit sells it as a rugged outdoor smartwatch.

Outdoor1Maker product pagecoros.com/apex4/specsRead 15 October 2026COROS calls it a mountain sports GPS watch for trail running, climbing and skiing. The store files it under GPS watches. Stored as outdoor.

OS updates promisediYears of explicitly promised OS updates. A security-only support period does not establish an OS-upgrade promise.

Not available

Not available

Security updates untiliExact end date published for security-update support of this model. Do not calculate it from a stated number of years. A security-only period does not promise OS upgrades.

Not available

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Case

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Case sizeiMarketed case-size options. The marketed size can differ from physical case height, such as ceramic editions. Base dimensions describe the smallest base-material case.

44, 48mm1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Two case sizes, 44 mm and 48 mm, sold as one product. Base values below describe the 44 mm case.7Press releasezepp.com/press-release/amazfit-t-rex-3-pro-smartwatch-launches-featuring-a-rugged-titanium-design-and-integrated-flashlightRead 15 October 2026Available in two case sizes, 48 mm and 44 mm.

42, 46mm1Maker product pagecoros.com/apex4/specsRead 15 October 2026Two sizes sold as one product, 42 mm and 46 mm. Base values describe the 42 mm case.

Case shape

Round1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026The display is round and the product images show a round case with an octagonal bezel.

Round1Maker product pagecoros.com/apex4/specsRead 15 October 2026Round case with a round Memory-in-Pixel display.

Case materialiMaterial of the housing body, not just the bezel. Use Mixed when the maker describes a mixture of housing/frame materials. Read the published-material field for the parts and proportions.

Mixed materials1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Body material: case in fiber-reinforced polymer. Bezel and buttons in Grade 5 titanium. Stored as mixed.

Mixed materials1Maker product pagecoros.com/apex4/specsRead 15 October 2026Materials: cover material Fiber Reinforced Polymer and bezel material Grade 5 Titanium Alloy. Stored as mixed.

Case material (as published)

Fiber-reinforced polymer case with Grade 5 titanium bezel and buttons1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026

Fiber Reinforced Polymer cover with Grade 5 Titanium Alloy bezel1Maker product pagecoros.com/apex4/specsRead 15 October 2026Materials: Cover Material Fiber Reinforced Polymer, Bezel Material Grade 5 Titanium Alloy.

BackiMaterial of the back of the smallest base-material case. Other materials or regional editions can differ. See source notes.

Not available

Not available

Case dimensionsiPhysical case height, width and thickness. The source note states exclusions such as the heart-rate sensor protrusion.

Height44.8Width44.8Thickness13.2mm(1.8 × 1.8 × 0.5 in)1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Dimensions without heart rate base: 48 mm 48 x 48 x 14 mm and 44 mm 44.8 x 44.8 x 13.2 mm. The thickness leaves out the sensor base.

Height42.6Width42.6Thickness14mm(1.7 × 1.7 × 0.6 in)1Maker product pagecoros.com/apex4/specsRead 15 October 2026Size and Weight, Dimensions: 42 mm 42.6 x 42.6 x 14 mm and 46 mm 46.2 x 46.2 x 13.7 mm. Height does not include the optical heart rate sensor. The 46 mm is thinner than the 42 mm as published. The5krunner repeats both figures.

Weight (case only)iWatch body without a strap. An unqualified published weight must not be assumed to exclude the strap.

46.8g(1.7 oz)1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Weight without strap: 48 mm 52 g and 44 mm 46.8 g.

Not available

Weight with strapiWatch with the stated strap attached. Strap material and case size belong in the source note. Reviewer measurements belong in measured fields.

Not available

44g(1.6 oz)1Maker product pagecoros.com/apex4/specsRead 15 October 2026Weight: 42 mm 44 g with nylon band and 56 g with silicone band. 46 mm 51 g with nylon band and 64 g with silicone band. The nylon band figure is stored. The maker publishes no case-only weight.3Maker product pagecoros.com/apex4Read 15 October 2026Overview: 51 g (46 mm) and 44 g (42 mm) with the nylon band.

Durability

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Water resistanceiStatic water-pressure rating in atmospheres. It is not a safe swimming or diving depth. Diving limits are listed separately.

10ATM1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Water-resistance grade 10 ATM. Note 6 says it is rated to ISO 22810:2010 for 100 m and passed SGS testing.

5ATM1Maker product pagecoros.com/apex4/specsRead 15 October 2026Durability: 5 ATM, suitable for surface water activities and not for diving. The buy page calls it WR50 certified.

Water resistance standard

ISO 22810:20101Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Note 6: according to ISO 22810:2010 the watch achieves 10 ATM.

Not available

Dust and water rating

Not available

Not available

Dive rating

EN13319:2000, ISO 6425:2018, GB/T 18828-20221Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Note 2 names EN13319:2000, ISO 6425:2018 and GB/T 18828-2022, each with report numbers per size.

Not available

Max dive depthiMaker-rated depth for the stated diving use, not a conversion from the water-resistance pressure rating.

45m1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Page text: certified for diving to a depth of 45 m. The comparison table lists 45 m freediving and scuba.

Not available

MIL-STD-810iMaker claim that the watch was tested against specified MIL-STD-810 methods. It is not a guarantee for every military-standard test.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Note 1: MIL-STD-810H-2019 data comes from report H202505284651-01EN for 48 mm and H202509017818-01EN for 44 mm. The tests are not listed.

Not available

MIL-STD-810 tests

Not available

Not available

Operating temperatureiPublished operating range. Source notes identify on-wrist limits and other operating conditions. Storage or charging limits are excluded.

Min-30°C7Press releasezepp.com/press-release/amazfit-t-rex-3-pro-smartwatch-launches-featuring-a-rugged-titanium-design-and-integrated-flashlightRead 15 October 2026The watch can operate in temperatures as low as -30 degrees C. No upper limit is published. The manual limits some functions below -10 degrees C on the watch surface.

Min-20Max50°C1Maker product pagecoros.com/apex4/specsRead 15 October 2026Durability: working temperature -4 F to 122 F (-20 C to 50 C). Storage temperature -20 C to 60 C is not stored.

Display

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Display type

OLED1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026

MIP1Maker product pagecoros.com/apex4/specsRead 15 October 2026Display: 3rd Generation Memory-in-Pixel touch screen.

Display type (as published)

AMOLED1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Display material: AMOLED.

3rd Generation Memory-in-Pixel touch screen1Maker product pagecoros.com/apex4/specsRead 15 October 2026Display, Display Type verbatim.

Screen sizeiPublished active display diagonal for a rectangular display, or diameter for a round display. Do not calculate it from pixels or display area.

1.32in(3.4 cm)1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Size: 48 mm 1.5 inch and 44 mm 1.32 inch.

1.2in(3 cm)1Maker product pagecoros.com/apex4/specsRead 15 October 2026Display Size: 1.2 inches on the 42 mm and 1.3 inches on the 46 mm.

Resolution

466 × 466px1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 202648 mm 480 x 480 and 44 mm 466 x 466.

240 × 240px1Maker product pagecoros.com/apex4/specsRead 15 October 2026Display Resolution: 240 x 240 on the 42 mm and 260 x 260 on the 46 mm.

Pixel densityiPublished pixel density. A rectangular diagonal formula must not be applied to a round display.

353ppi1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026PPI 322 for 48 mm and 353 for 44 mm as published.

Not available

Display area

Not available

Not available

Touchscreen

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026The manual describes swipe gestures and touch. The spec table row labelled Touchscreen names sapphire glass.6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Gestures such as swipe and tap. The touchscreen is switched off during dives.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Display Type says touch screen. The feature list names Touch Scroll.

Max refresh rateiHighest published display refresh rate in active operation.

Not available

Not available

Min refresh rateiLowest published display refresh rate, usually in always-on mode. It is not the active-use minimum unless stated.

Not available

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Peak brightnessiMaker peak-brightness claim. It may apply to a small area or bright ambient light. Full-screen limits and battery/temperature conditions belong in source notes.

3,000nits1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Peak brightness up to 3,000 nits. Note 16: not supported in low temperature mode or when battery life is below 30%, and needs automatic brightness.

Not available

Minimum brightness

Not available

Not available

Always-on display

Yes6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Settings > Display > Always On Display, and an Always-on mode toggle in the Control Center.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Daily Features list Always-On Display. The overview calls it a 3rd generation always-on MIP display.

Display cover

Sapphire1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 20267Press releasezepp.com/press-release/amazfit-t-rex-3-pro-smartwatch-launches-featuring-a-rugged-titanium-design-and-integrated-flashlightRead 15 October 2026Scratch-resistant sapphire glass screen.

Sapphire1Maker product pagecoros.com/apex4/specsRead 15 October 2026Materials: Screen Material Sapphire Glass.

Display cover (as published)

Sapphire glass1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Screen material: sapphire glass. The features text says scratch-resistant sapphire glass.

Sapphire Glass1Maker product pagecoros.com/apex4/specsRead 15 October 2026Materials: Screen Material Sapphire Glass.

Platform

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Platform

Proprietary1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Zepp OS, Zepp Health's own operating system. The page links to the Zepp OS technology page.

Proprietary1Maker product pagecoros.com/apex4/specsRead 15 October 2026COROS own firmware, updated through Wi-Fi and the COROS app. No Wear OS, watchOS or HarmonyOS.

OS at launch

Zepp OS 53Maker product pageuk.amazfit.com/products/t-rex-3-proRead 15 October 2026The UK comparison table lists Zepp OS 5 for the T-Rex 3 Pro. The US page now lists Zepp OS 6.4Maker product pagede.amazfit.com/products/t-rex-3-proRead 15 October 2026Specs table lists Zepp OS 5.8Spec databasethe5krunner.com/specs/amazfit/t-rex-3-proRead 15 October 2026Operating system Zepp OS 5.

Not available

Software

Not available

Not available

Latest OS

Zepp OS 61Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026The comparison table on the US page lists OS compatibility Zepp OS 6. The UK page still lists Zepp OS 5.10Press articlegadgetsandwearables.com/2026/07/22/amazfit-t-rex-3-pro-ultra-2-zepp-os-6-updateRead 15 October 2026Article of 22 July 2026: Zepp OS 6 rolls out to the T-Rex 3 Pro, with firmware 6.2.104.6 in the screenshot.

Not available

Works with

iOS, Android1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 20266Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Pairs with the Zepp App on Android or iOS.

Not available

Phone requirement

Android 7.0 and above, iOS 15.0 and above, with the Zepp App1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Supported devices: Android 7.0 and above, iOS 15.0 and above. Application: Zepp App.6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Manual: the phone must run Android 7.0 or iOS 15.0 or later.

Not available

App store

Yes6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Apps can be installed from the app store in the Zepp App.

No18Reviewoutdoorgearlab.com/reviews/camping-and-hiking/gps-watch/coros-apex-4Read 15 October 2026The review says the watch has no third-party apps and no contactless payments.

Voice assistants

Zepp Flow1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026AI assistant: Zepp Flow, in select countries and regions.

Not available

Chipset

Not available

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Process

Not available

Not available

CPU cores

Not available

Not available

CPU configuration

Not available

Not available

Max CPU clock

Not available

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GPU

Not available

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Low-power coprocessor

Not available

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Memory

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RAMiKeep published GB values as stated. Convert a source explicitly labelled MB using 1000 MB per GB and preserve its original figure and unit in the note. Do not assume MB means MiB. Convert explicit MiB or GiB to decimal GB through their byte definitions, recording the conversion in the note. This normalization does not establish an exact physical byte count.

Not available

Not available

StorageiTotal built-in storage the maker states, in decimal GB. Space available to the user is lower and goes in the source note. A figure the maker gives only as available space is not stored.

Not available

32GB1Maker product pagecoros.com/apex4/specsRead 15 October 2026Memory: internal memory 32 GB, with room for 1200 hours of activity data (estimate based on outdoor activities).

Health sensors

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Heart rate sensor

BioTracker 6.0 PPG biometric sensor (5PD + 2LED)1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Health sensor: BioTracker 6.0 PPG biometric sensor (5PD + 2LED).

Optical heart rate monitor1Maker product pagecoros.com/apex4/specsRead 15 October 2026Data Tracking: Optical Heart Rate Monitor (may not work over tattoos). The sensor generation is not named.

ECG capabilityiElectrical heart sensing hardware with an ECG capability. The ECG app can require an eligible country, age and paired phone.

Not available

Not available

Blood oxygen sensingiBlood-oxygen sensing capability. App availability and medical status vary by market.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 202624 hour and manual blood-oxygen saturation. Not a medical device.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Data Tracking: Optical Pulse Oximeter.

Skin temperature sensingiA sensor or supported function that measures skin temperature. It is not a core-body thermometer.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 202624H monitoring lists skin temperature (thermometer).

Not available

Blood pressure featureiPublished blood-pressure feature category. Hypertension notifications are not numerical blood-pressure readings.

Not available

Not available

Body composition sensor

Not available

Not available

Skin conductance (EDA)

Not available

Not available

Medical clearancesiNamed regulatory clearances and their jurisdiction. General water resistance or an ECG sensor does not establish medical clearance.

Not available

Not available

Motion and environment sensors

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Accelerometer

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Data Tracking: Accelerometer.

Accelerometer range

Not available

Not available

Gyroscope

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Data Tracking: Gyroscope.

Barometric altimeter

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Data Tracking: Barometric Altimeter. The overview names a dual-range barometer.

Compass

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Outdoor tools list Compass and the movement sensors include a geomagnetic sensor.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Data Tracking: 3D Compass.

Ambient light sensor

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Movement sensors list an ambient light sensor.

Not available

Depth gauge

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026The comparison table lists scuba and freediving with dive depth. The manual states the maximum measurement depth.6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Technical specifications in the diving section state the maximum measurement depth.

Not available

Depth gauge rangeiPublished measurement range of the depth gauge, distinct from maximum diving depth and water-pressure resistance.

45m1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026See the manual for the 45 m maximum measurement depth.6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Maximum measurement depth: 45 m / 147.6 ft. Accuracy follows EN13319.

Not available

Water temperature sensor

Not available

Not available

Health and fitness

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Health featuresiSupported health functions with country, phone and subscription restrictions in the source notes. Upcoming functions are not counted as available.

Continuous heart rate, Heart rate alerts, Blood oxygen app, Heart rate variability, Sleep tracking, Sleep stages, Stress tracking, Readiness score1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 202624 hour heart rate, blood oxygen and stress, abnormal high and low heart rate alerts, sleep heart rate variability, sleep stages including REM, and HybridCharge energy score. Not medical devices.

Blood oxygen app, Heart rate variability, Sleep tracking, Sleep stages, Stress tracking1Maker product pagecoros.com/apex4/specsRead 15 October 2026Daily Features: Daily Stress, Sleep (with REM tracking), HRV, Wellness Check. Data Tracking: Optical Pulse Oximeter. Continuous heart rate is not stored because the page does not state it. The Electrical Heart Rate Sensor is for HRV and wellness checks, so no ECG is stored.7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026Sleep and Wellness Features: sleep and nap tracking, overnight HRV and wellness checks. Control Center has an Oximeter for SpO2 readings.

Fitness featuresiSupported workout functions. A sport-profile name alone does not prove advanced metrics such as running power or running dynamics. Trackback follows the recorded route back to the start. A compass arrow that points straight to the start does not count.

Automatic workout detection, VO2 max, Training load, Recovery advice, Pool swim, Open water swim, Strength rep counting, Interval workouts, Route navigation, Turn-by-turn navigation, Trackback, Golf courses, Ski resort maps1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Smart recognition of 8 sports movements, VO2 Max, Training Load, recovery, pool and open-water swim, strength training with recognition of 25 movements, interval training, offline maps, turn-by-turn directions, direct return navigation and ski resort maps. The FAQ says Golf Mode is supported with golf course maps.6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Navigation section: return to the starting point by straight line or by the original route (Backtrack).

VO2 max, Training load, Recovery advice, Pool swim, Open water swim, Interval workouts, Route navigation, Turn-by-turn navigation, Trackback1Maker product pagecoros.com/apex4/specsRead 15 October 2026Training Features: EvoLab with recovery, fatigue, training load and VO2 max, Basic Interval Training, Training Plans. Navigation: Landscape and Topo map layers, turn-by-turn directions and Back-To-Start. Supported Activity Modes list Open Water and Pool Swim. Running dynamics need a COROS POD, so they are not stored.13Maker product pagecoros.com/stories/latest-news/c/get-more-from-navigationRead 15 October 2026COROS blog: Back to Start uses the GPS points logged during the activity and guides you back along the same path. The spec page lists Back-To-Start for the APEX 4 and the Using Navigation Features article lists the APEX 4.

Sport profilesiPublished count of distinct sport/activity profiles. A claim such as 180+ is not an exact integer count.

1871Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Technical specifications row: Sports Modes 187. Marketing copy says 180+.

Not available

Dive modesiActual supported dive modes. Water resistance or a depth app alone does not establish decompression-capable scuba support.

Scuba, single gas, Freedive1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Comparison table: 10 ATM, 45 m freediving, scuba. The FAQ says it suits freediving and recreational scuba diving.6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Diving section: the device supports recreational scuba diving and freediving modes. The default gas type is Air and it must not be used for mixed-gas or technical diving.

Not available

External sensorsiTypes of external workout sensors the watch can pair with. GPS reception, phone data and built-in sensors do not qualify.

Heart rate strap, Power meter, Speed and cadence, Foot pod, Smart trainer1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Bluetooth peripherals: heart rate belt, running power meter, cycling power meter, cycling speed and cadence sensors and Stryd foot pod. The September 2026 update notes add FTMS indoor bike trainers. Only BLE devices are supported.

Heart rate strap, Power meter1Maker product pagecoros.com/apex4/specsRead 15 October 2026Connectivity: accessories over Bluetooth. Training Features: Running Form Test requires COROS POD or POD 2. The buy page FAQ names BLE heart rate monitors and cycling power. No other sensor types are stated.4Maker product pagecoros.com/buy/apex4Read 15 October 2026FAQ: external sensors over BLE for HRM, cycling power and more.7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026The guide names no sensor types.

Safety

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Fall detectioniAutomatic fall detection. Incident detection restricted to recorded workouts is not counted as general fall detection.

Not available

Not available

Car crash detection

Not available

Not available

Emergency SOSiA manual emergency alert to emergency services or preset contacts. Source notes identify the recipient, paired-phone requirement and country limits. Satellite is listed separately.

Not available

Yes10Maker product pagesupport.coros.com/hc/en-us/articles/25514157012116-Safety-AlertsRead 15 October 2026The APEX 4 is on the device list. Press and hold the dial for 7 seconds, then press once to confirm. Preset contacts (up to 3) get a text with a live location link. Needs the paired phone with cell service. It does not contact local emergency services.

Emergency sireniPublished or measured siren sound level in decibels. Audible distance alone does not establish this value. Measurement distance belongs in source notes.

Not available

Not available

Live location sharingiShares live location during supported use. A paired phone or data subscription may be required.

Not available

Yes11Maker product pagesupport.coros.com/hc/en-us/articles/51716258730772-How-to-Use-Live-TrackingRead 15 October 2026The APEX 4 is on the device list. Live Tracking works for outdoor activities and needs the phone connected with the COROS app running.

Dedicated LED flashlightiA dedicated hardware LED flashlight. Lighting the display white is not counted.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Two-color LED flashlight: 200 lux and 300 lux in Boost Mode.7Press releasezepp.com/press-release/amazfit-t-rex-3-pro-smartwatch-launches-featuring-a-rugged-titanium-design-and-integrated-flashlightRead 15 October 2026Dual-color LED flashlight with Boost mode, red light and SOS flash.

Not available

Positioning

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PositioningiPublished satellite systems and signal bands. Do not infer bands from dual-frequency support alone.

Not available

GPS, GLONASS, Galileo, BeiDou, QZSS1Maker product pagecoros.com/apex4/specsRead 15 October 2026Geo Location, Satellite Systems: GPS, GLONASS, Galileo, Beidou, QZSS.

Dual-band GNSSiMaker-stated dual-frequency satellite reception. Supported constellations and signal bands are listed separately.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Positioning: dual-band support and six satellite positioning systems. The page does not name the systems.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Geo Location: GNSS chipset All-Satellite Dual-Frequency.

Offline mapsiMap data stored on the watch and usable without live phone data. GPX routes or breadcrumb tracks alone are not offline maps.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Navigation and maps: offline maps supported.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Navigation: map layers Landscape and Topo as downloadable global maps. The setup guide downloads maps to the watch through Map Manager.7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026Maps and Navigation: download global landscape and topographic maps to the watch in the COROS app Map Manager.

Connectivity

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BluetoothiPublished Bluetooth support for this model. The version is recorded separately. Unknown version does not mean the radio is absent.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Connection: Wi-Fi 2.4 GHz, Bluetooth 5.2, BLE.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Connectivity: phone and accessories connect over Bluetooth.

Bluetooth version

5.21Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 20264Maker product pagede.amazfit.com/products/t-rex-3-proRead 15 October 2026Specs table: Bluetooth 5.2 (BLE) and 2.4 GHz Wi-Fi.

5.416Regulatory filingfccid.co/api/files/s2/fccids/2BBGF-W542/files/4fa28337_SAR_report.pdfRead 15 October 2026Test report CTB25071300230RH04 (W542, issued 2025-08-23): Bluetooth Version 5.4, with BLE and EDR.

Wi-FiiPublished Wi-Fi support for this model. The standard and bands are recorded separately. Unknown standard does not mean Wi-Fi is absent.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Connection: Wi-Fi 2.4 GHz and OTA update via Wi-Fi.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Connectivity: data sync over Wi-Fi and the COROS app.

Wi-Fi standard

Not available

Wi-Fi 616Regulatory filingfccid.co/api/files/s2/fccids/2BBGF-W542/files/4fa28337_SAR_report.pdfRead 15 October 2026Same report: Wi-Fi specification 2.4G IEEE 802.11b/g/n/ax, so Wi-Fi 6 on 2.4 GHz.

Wi-Fi bands

2.4 GHz1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 20264Maker product pagede.amazfit.com/products/t-rex-3-proRead 15 October 2026Specs table: 2.4 GHz Wi-Fi.

2.4 GHz16Regulatory filingfccid.co/api/files/s2/fccids/2BBGF-W542/files/4fa28337_SAR_report.pdfRead 15 October 2026Same report: Wi-Fi 2412-2462 MHz, 11 channels. No 5 GHz band is listed.

CellulariTrue when a cellular edition is sold. A variant row states whether that individual model has cellular hardware.

No1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Connection lists Wi-Fi 2.4 GHz, Bluetooth 5.2 and BLE only. No cellular radio is listed.

No1Maker product pagecoros.com/apex4/specsRead 15 October 2026Connectivity lists Bluetooth and Wi-Fi only. No cellular radio is listed.

Network

Not available

Not available

4G bandsiPublished LTE bands for the stated regional cellular model. Do not transfer bands to another region or Wi-Fi-only model.

Not available

Not available

5G bandsiPublished 5G NR bands for the stated regional cellular model. RedCap support does not establish conventional full-bandwidth phone 5G.

Not available

Not available

NFCiSome regions sell an NFC edition, so it is per variant.

Yes3Maker product pageuk.amazfit.com/products/t-rex-3-proRead 15 October 2026The Zepp Pay text says Zepp Pay uses the integrated NFC technology.4Maker product pagede.amazfit.com/products/t-rex-3-proRead 15 October 2026Zepp Pay text names the integrated NFC technology.8Spec databasethe5krunner.com/specs/amazfit/t-rex-3-proRead 15 October 2026Lists NFC for Zepp Pay.

No17Spec databasethe5krunner.com/specs/coros/apex-4Read 15 October 2026NFC: No. The maker's FAQ says payment is not supported.

Contactless payments

Yes3Maker product pageuk.amazfit.com/products/t-rex-3-proRead 15 October 2026Zepp Pay binds up to eight bank cards for contactless payment. Note 16 lists 31 supported countries in Europe through Curve and issuer banks. The US page does not mention Zepp Pay.

No4Maker product pagecoros.com/buy/apex4Read 15 October 2026FAQ: Payment is not supported.

Payment services

Zepp Pay3Maker product pageuk.amazfit.com/products/t-rex-3-proRead 15 October 2026Zepp Pay. Curve and participating issuer banks in 31 European countries.

Not available

Ultra-wideband

Not available

Not available

Satellite

Not available

None1Maker product pagecoros.com/apex4/specsRead 15 October 2026Connectivity lists Bluetooth and Wi-Fi only. No satellite link is listed.

ANT+

No1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Note 15: peripheral connections only support BLE devices. ANT+ is not listed.

No1Maker product pagecoros.com/apex4/specsRead 15 October 2026Connectivity: accessories over Bluetooth. ANT+ is not listed.17Spec databasethe5krunner.com/specs/coros/apex-4Read 15 October 2026ANT+: No.

Audio

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Speaker

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Mic and Speaker: Support.7Press releasezepp.com/press-release/amazfit-t-rex-3-pro-smartwatch-launches-featuring-a-rugged-titanium-design-and-integrated-flashlightRead 15 October 2026Built-in speaker and microphone.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Data Tracking: speaker to take hands-free calls or play activity alerts out loud.

Microphones

Not available

Not available

Calls on the watchiVoice-call capability of the marketed model, including sold cellular editions. Variant radio capability and paired-phone requirements still apply.

Phone only1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026FAQ: the T-Rex 3 Pro supports Bluetooth phone calls and texts. Calls use the paired phone.

Phone only1Maker product pagecoros.com/apex4/specsRead 15 October 2026Speaker to take hands-free calls. The watch has no cellular radio, so calls go through the paired phone. Daily Features: Message/Call Alert.

Music on the watchiPlays audio stored on the watch. Remote control of phone playback or streaming alone does not qualify.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Music storage: Support, with a 26 GB shared storage limit. The manual says local music plays through the speaker or Bluetooth headphones.6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Music player: plays .mp3 files stored on the watch through the speaker or Bluetooth headphones.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Daily Features: Music, plays offline music when paired with supported Bluetooth headsets.4Maker product pagecoros.com/buy/apex4Read 15 October 2026FAQ: offline MP3 music is available directly from the watch.

Controls

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ButtonsiPhysical controls used to operate the watch, excluding the rotating crown and strap-release buttons. A clickable rotating crown is counted only in Crown.

41Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Buttons: 4.6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026UP, SELECT, BACK and DOWN. UP and DOWN also work as gesture shortcuts.

21Maker product pagecoros.com/apex4/specsRead 15 October 2026Design lists Digital Dial, Back Button and Action Button. The dial is a rotating control and is not counted in the two buttons.7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026Operating APEX 4 lists the dial, the Back/Lap button and the Action button.

Named operating buttonsiNames of operating buttons, excluding the crown and strap-release controls.

UP, SELECT, BACK, DOWN6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Upper right SELECT, lower right BACK, plus UP and DOWN.

Back/Lap Button, Action Button1Maker product pagecoros.com/apex4/specsRead 15 October 2026Design: Back Button and Action Button.7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026Operating APEX 4: Digital Dial (top right), Back/Lap Button (bottom right) and Action Button (bottom left).

CrowniA crown that rotates to control the interface. A round push button that does not rotate is not a crown.

None6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026No crown is described. Controls are four buttons and the touchscreen.

Rotating1Maker product pagecoros.com/apex4/specsRead 15 October 2026Design: Digital Dial. The setup guide says to scroll the dial to move the selection and press to confirm. No haptic claim.7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026Digital Dial: scroll to move the selection, press to confirm.

Rotating bezeliPhysical rotation or touch gestures around the display edge. A fixed decorative bezel is None.

None6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026No rotating bezel is described.

Not available

Gestures

Not available

Not available

Battery and charging

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Battery capacityiPublished battery capacity for the stated case size. Rated and typical capacity are distinguished in source notes.

500mAh1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Battery capacity: 48 mm 700 mAh and 44 mm 500 mAh, both rated values.

Not available

Claimed battery lifeiMaker endurance claims with distinct operating modes and case sizes. With solar describes augmentation of that estimate, not hardware capability. Use false for ordinary claims without solar augmentation, true for explicitly solar-aided claims, and omit it when solar qualification is unclear. Source notes state AOD, GNSS, music and solar conditions. Do not create a normal-use row from an AOD-only claim. Low power denotes the maker battery-saver mode. Keep its typical, light-use and always-on claims separate from standard-mode claims. GPS power saving identifies an intermediate reduced-accuracy GNSS saving preset. Source notes retain the maker's preset name and published conditions. Max battery GPS is the distinct maximum-saving claim. When the maker has only one GPS saving preset, it is GPS power saving.

AAmazfit T-Rex 3 Pro

Mode	With solar	Hours (h)
Smartwatch	No	408
Heavy use	No	192
GPS, dual-band	No	26
GPS, power saving	No	51
Extended GPS workout	No	60
Max battery GPS	No	86

Source1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Typical use 25 days (48 mm) and 17 days (44 mm). Heavy use 10 days and 8 days. Accurate GPS mode 38 h and 26 h in the spec table, with heart rate on and dual-frequency, all satellites. Power-saving GPS 74 h and 51 h with single frequency. GPS Long Battery Life 85 h and 60 h and GPS Max Battery Life 116 h and 86 h, both only in Hiking and Climbing sports modes. Low temperature rows are not stored. The comparison table shows 29 h for the 44 mm accurate GPS value. The spec table, feature text and UK page say 26 h, so 26 h is stored. Conditions are in note 8.3Maker product pageuk.amazfit.com/products/t-rex-3-proRead 15 October 2026The UK page gives 26 h for the 44 mm accurate GPS mode, like the US spec table.

BCOROS APEX 4

Mode	With solar	Hours (h)
Smartwatch	No	360
GPS, automatic system selection	No	41
GPS, automatic system selection with music	No	11
GPS, all systems	No	34
GPS, all systems with music	No	10
GPS, dual-band	No	26
GPS, dual-band with music	No	9

Source1Maker product pagecoros.com/apex4/specsRead 15 October 2026Battery table. 42 mm: Endurance All Systems 41 h (11 h with offline music), All Systems On 34 h (10 h), Dual Frequency 26 h (9 h), Daily Use 15 days. 46 mm: Endurance 65 h (17 h), All Systems On 53 h (16 h), Dual Frequency 41 h (15 h), Daily Use 24 days. Days are converted to hours exactly. The Battery Specifications article names the daily use row as sleep tracking plus daily stress. The setup guide says the Endurance preset picks satellite systems intelligently, so it is stored as GPS automatic system selection. Always-on display use in these figures is not stated. The standard GPS row is empty.3Maker product pagecoros.com/apex4Read 15 October 2026Overview: up to 65 hours of All Systems GPS on the 46 mm or 41 hours on the 42 mm, marked as Endurance Satellite Mode. Matches the spec table.9Maker product pagesupport.coros.com/hc/en-us/articles/23476623096980-Battery-SpecificationsRead 15 October 2026APEX 4 (42) table: Endurance 41 h, All Systems On / High 34 h, Dual Frequency / Max 26 h, daily use with sleep tracking and daily stress 15 days. APEX 4 (46): Endurance 65 h, All Systems 53 h, Dual Frequency 41 h, daily use 24 days. Same figures as the spec page. Actual use can be higher with backlight, navigation and accessories.

Smartwatch mode (claimed)iMaker normal-use smartwatch claim without solar. A watch with only an explicit AOD-mode claim has no value here. Workloads differ and source notes must be read.

408h=CalculatedFrom Claimed battery life

360h=CalculatedFrom Claimed battery life

AOD battery life (up to)iMaker claimed smartwatch endurance with the always-on display enabled and without solar, for the base case. Source notes preserve workload and case conditions. This is a claim, not a measured test or an AOD-off estimate.

Not available

Not available

GPS mode (claimed)iMaker regular GPS/GNSS activity claim without solar, for the base case. AOD, multi-band, music and power-saving conditions have separate rows when published.

Not available

Not available

Solar chargingiPublished solar charging hardware capability. An ordinary battery estimate without solar augmentation does not prove that the watch lacks solar charging hardware.

Not available

Not available

Charging methodiThe connection at the watch, not the cable end at the USB adapter. A proprietary inductive puck is not Qi unless interoperability is explicitly established.

Not available

Proprietary plug7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026Charging APEX 4: metal pins on the A2 adapter fit into the charging port on the back of the watch and snap into place. A standard USB-C cable connects to the adapter.8Owner's manualsupport.coros.com/hc/en-us/articles/41966405480340Read 15 October 2026Charging Your APEX 4: the adapter pins fit into the port on the back and the adapter takes any standard USB-C cable. Charging works during an activity.

Charging guidanceiPublished charging requirements, nominal estimates and compatibility guidance. Keep adapter ratings separate from power accepted by the watch.

Magnetic charging head. The packing list says no cable is included and the store FAQ says a USB-C cable is not supplied.1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Packing list: magnetic charging head (no cable). FAQ: Amazfit does not include a USB-C cable.

The COROS A2 charging adapter clips onto the pins on the back of the watch and takes any standard USB-C cable. COROS asks for an LPS-certified charger and official accessories only. It says not to use a battery pack with quick-charge capability. The store FAQ says 0 to 100% in under 2 hours.4Maker product pagecoros.com/buy/apex4Read 15 October 2026FAQ: 0 to 100% in under 2 hours. The box note says the USB-C charging cable is not included.8Owner's manualsupport.coros.com/hc/en-us/articles/41966405480340Read 15 October 2026Use an LPS-certified charger. Use official accessories only. Do not use a power bank with quick-charge capability.

Max charging power (watch)iPublished maximum charging power at the watch. Adapter rating or charger input power does not prove the power accepted by the watch.

Not available

Not available

Fast chargingiAn explicit fast-charging capability claim. A short charging time or high adapter wattage alone does not qualify.

Not available

Not available

Quick charge claimiMaker claim for usage from a short charge. Source notes identify the usage workload, such as normal use or sleep tracking.

Not available

Not available

Charge 0 to 80% (claimed)iMaker claim for charging an empty battery to 80%. Charger and approximate qualifiers belong in source notes.

Not available

Not available

Full charge time (claimed)iMaker advertised nominal full-charge duration. Approximate or theoretical maker estimates are allowed, with their conditions in source notes. Partial-charge intervals do not qualify. Measured 0 to 100% tests have a separate field.

Not available

Not available

Measured

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Peak brightness (measured)iReviewer measurement. Source notes state screen area, mode and ambient light. A small-area peak claim cannot be replaced with a full-screen measurement.

Not available

Not available

Battery life (measured)iReviewer-observed mixed-use endurance. Source notes state case size, AOD, workout use and whether it was a complete discharge. Extrapolation from partial discharge is excluded.

Not available

Not available

Battery tests (measured)iReviewer-observed endurance, with case size and test settings in source notes. Partial-discharge projections are not stored as measured endurance.

Not available

Not available

Full charge time (measured)iReviewer measurement from empty to full, not 0-80% or a charge from 5%. Source notes name the charger and case size.

Not available

101min18Reviewoutdoorgearlab.com/reviews/camping-and-hiking/gps-watch/coros-apex-4Read 15 October 2026The review reports about 101 minutes from empty to full with the USB-C charging adapter on the 46 mm model tested. The charger and power source are not stated. The claim is under 2 hours.

Strap

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Lug widthiDistance between standard strap attachment lugs, not the decorative width of a proprietary strap. Unknown for custom connectors unless the maker publishes lug width.

20mm1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Strap width: 48 mm 22 mm and 44 mm 20 mm.

22mm1Maker product pagecoros.com/apex4/specsRead 15 October 2026Strap: width 22 mm on the 42 mm case and 24 mm on the 46 mm case.

Quick-release strapiThe supplied strap can be detached through its quick-release mechanism. Compatibility with quick-release replacement straps alone does not qualify.

Yes1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Comparison table: strap attachment 22 mm quick release and 20 mm quick release.

Yes1Maker product pagecoros.com/apex4/specsRead 15 October 2026Strap: installation type Quick Release.

Strap systemiPublished attachment system and compatible case sizes. Proprietary connectors are distinguished from standard spring bars.

20 mm quick release on the 44 mm case and 22 mm quick release on the 48 mm case1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Comparison table: strap attachment 22 mm quick release for 48 mm and 20 mm quick release for 44 mm.

Quick release, 22 mm on the 42 mm case and 24 mm on the 46 mm case1Maker product pagecoros.com/apex4/specsRead 15 October 2026Strap: width 22 mm (42 mm) and 24 mm (46 mm), installation type Quick Release.

Strap materialiMaterial of the supplied strap for the stated package. Do not substitute material from another band sold separately.

Silicone1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Strap material: silicone.

Not available

Strap

Not available

Not available

Strap sizesiPublished wrist-circumference range for the stated strap or case. Source notes distinguish an overall compatible wrist range from one supplied strap size.

AAmazfit T-Rex 3 Pro

Wrist (min) (mm)	Wrist (max) (mm)
140	205

Source1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Min and max wrist dimensions: 48 mm 145 to 210 mm and 44 mm 140 to 205 mm. Buckle: classic pin buckle.

BCOROS APEX 4

Size	Wrist (min) (mm)	Wrist (max) (mm)
Nylon and silicone	135	205

Source1Maker product pagecoros.com/apex4/specsRead 15 October 2026Strap: 135-205 mm for silicone and nylon on the 42 mm. 140-215 mm for both on the 46 mm. The spec page lists size ranges per strap material with the same numbers.

Regulatory

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FCC ID

Not available

2BBGF-W542, 2BBGF-W54114Regulatory filingfccid.co/fcc/2BBGF-W542Read 15 October 2026FCC ID 2BBGF-W542 is COROS APEX 4 42mm, grant date Nov 28, 2025. Read on a public mirror of the FCC filing.15Regulatory filingfccid.co/fcc/2BBGF-W541Read 15 October 2026FCC ID 2BBGF-W541 is COROS APEX 4 46mm, grant date Nov 27, 2025.

SAR limb (US)iPublished limb/wrist SAR for the stated base regional model under the US regime. Other case sizes or radio versions can differ. Head or body SAR is excluded.

Not available

0.48W/kg16Regulatory filingfccid.co/api/files/s2/fccids/2BBGF-W542/files/4fa28337_SAR_report.pdfRead 15 October 2026Same report, W542 (42 mm): maximum reported 10 g wrist-worn SAR 0.48 W/kg at 0 mm (Wi-Fi 2.4 GHz). Limit 4.0 W/kg. The 46 mm W541 report (CTB25071300229RH04) gives 0.52 W/kg. US regime.

SAR limb (EU)iPublished limb/wrist SAR for the stated base regional model under the EU regime. Other case sizes or radio versions can differ. Head or body SAR is excluded.

Not available

Not available

Other certifications

Not available

Not available

In the box

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In the box

Smartwatch (including standard strap), Magnetic charging head (no cable), Instruction manual1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Packing list: smartwatch (including standard strap), magnetic charging head (no cable), instruction manual.

COROS APEX 4 GPS Watch, COROS A2 Charging Adapter7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026What's In the Box: COROS APEX 4 GPS Watch and COROS A2 Charging Adapter. The buy page says no USB-C cable is included.

Power adapter in boxiA mains/USB power adapter is supplied. A charging cable, inductive puck or charging dock alone does not count.

No1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Only the charging head is supplied. No mains adapter and no cable.

No7Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026The box has the A2 adapter and no USB-C cable or power adapter.

Links

Not compared

Product page

us.amazfit.com/products/t-rex-3-pro1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026

coros.com/apex43Maker product pagecoros.com/apex4Read 15 October 2026The maker's product overview page.

Spec sheet

Not available

coros.com/apex4/specs1Maker product pagecoros.com/apex4/specsRead 15 October 2026The maker's technical specifications page.

Manual

support.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdf6Owner's manualsupport.amazfit.com/en/amazfit_t-rex_3_pro/files/user-manual.pdf.pdfRead 15 October 2026Amazfit T-Rex 3 Pro user manual, global version.

support.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-47Owner's manualsupport.coros.com/hc/en-us/articles/42070715941268-Set-Up-Your-COROS-APEX-4Read 15 October 2026Setup guide for the APEX 4, last edited 2026-10-14. COROS publishes no separate PDF manual.

EPREL registration numberiId in the EU energy label database. Each size or model of a series has its own id, so it is per variant.

Not available

Not available

Warranty

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Manufacturer warranty (source market)iThe maker's warranty period for the exact SKU or configuration and market named in the source note. It applies only to that stated market, not every regional variant. Statutory consumer rights are excluded. The base term is stored. An extension that needs registration goes in the source note.

1year1Maker product pageus.amazfit.com/products/t-rex-3-proRead 15 October 2026Store footer says 1 Year Warranty. This is the US store.

2years12Maker product pagesupport.coros.com/hc/en-us/articles/360039803532-COROS-Warranty-PolicyRead 15 October 2026COROS offers a 2-year warranty from the original activation date for watches. Straps have 180 days. Local consumer law rights may differ.

Both are also in the API. Back to all smartwatches.