Amazfit T-Rex 3 (48 mm) / Apple Watch Ultra (49 mm, 1st generation)

Amazfit T-Rex 3 (48 mm): 48.5 mm case, 1.5-inch AMOLED; Onyx (black), Lava and Gray colours. The T-Rex 3 Pro, T-Rex 2 and the T-Rex Ultra 2 are separate models.

Apple Watch Ultra (49 mm, 1st generation): Apple Watch Ultra, 49 mm natural titanium case, GPS + Cellular. The Apple Watch Ultra 2 and Ultra 3 are separate models.

Specification	Amazfit T-Rex 3 (48 mm)	Apple Watch Ultra (49 mm, 1st generation)
Release year	2024	2022
Display	1.5-inch AMOLED, 480 × 480 pixels, 322 ppi; Gorilla Glass touchscreen There is also a night display mode. Amazfit	LTPO2 OLED always-on Retina; 410 × 502 pixels; 1185 mm² display area; up to 2000 nits LTPO lets the refresh rate drop very low, so the screen can stay on without draining the battery. 2000 nits was twice as bright as any earlier Apple Watch display. Apple
Case and strap	48.5 × 48.5 × 13.75 mm; stainless-steel bezel, polymer middle frame; 4 buttons; 22 mm liquid-silicone strap for 145–210 mm wrists The 22 mm strap is a standard width and can be swapped. Amazfit	—
Weight	68.3 g (without strap) Amazfit	61.3 g (without band) Apple
Water and diving	10 ATM; freediving to 45 metres (147 ft) certified to EN 13319, ISO 6425 and GB/T 18828 10 ATM means withstanding the pressure of 100 metres of still water for up to 10 minutes. Breath-hold training and testing are downloaded through the Zepp app. Amazfit	—
Battery	700 mAh; 27 days typical, 13 days heavy use, 40 days battery saver, 81 days clock mode; 42 hours in accuracy GPS mode, 72 hours power-saving GPS, 180 hours maximum GPS mode A full charge takes about 3 hours; a magnetic charging base is in the box but no USB-C cable. Low-temperature mode gives 28 hours with GPS on and 32 days with it off. The maximum GPS mode works only in hiking and climbing modes. Amazfit	Up to 36 hours; up to 18 hours with LTE; USB-C magnetic fast-charging cable Runtime depends on display, workout and cellular use; using LTE away from the phone drains the battery noticeably faster. Apple
Positioning and navigation	Dual-band and single-band modes; 6 satellite systems; offline maps, turn-by-turn directions, route import, back-to-start and off-route alerts Dual-band positioning receives two frequencies from the satellites to reduce drift from reflected signals among tall buildings and dense trees; it uses more battery. Automatic mode switches settings based on signal strength. Amazfit	—
Sensors	BioTracker 6.0 PPG biometric sensor; accelerometer, gyroscope, magnetometer, barometric altimeter, ambient light, temperature sensor The watch offers an altitude assistant, storm alerts, compass, sunrise/sunset and tide information, and prompts for blood-oxygen readings at high altitude. Amazfit	—
Connectivity	Bluetooth 5.2 (BLE), 2.4 GHz Wi-Fi; microphone; music storage Wi-Fi is used to download software updates without the phone. The watch shows incoming calls but cannot take Bluetooth calls; quick reply works on Android only. Amazfit	LTE and UMTS; Wi-Fi 802.11b/g/n 2.4 and 5 GHz; Bluetooth 5.3 With cellular, the watch can make calls and get messages without the phone nearby; carrier support is required. Apple
Sports and health	170+ sports modes (177 listed); recognition of 25 strength and 8 sports movements; 24-hour heart rate, blood oxygen and stress; sleep stages; PAI; Zepp Coach Chest straps, running/cycling power meters and cycling speed/cadence sensors can be paired; data can be exported to apps such as Strava, komoot and Apple Health. Amazfit	—
Compatibility	Android 7.0 and later, iOS 14.0 and later; Zepp app Amazfit	iPhone 8 or later with iOS 16 or later The watch can only be set up and used with an iPhone; it does not pair with Android phones. Apple
Case and glass	—	49 mm natural titanium case; flat sapphire front crystal; ceramic and sapphire back The flat front crystal is protected by a raised titanium edge. Apple
Chip	—	S8 SiP with 64-bit dual-core processor; W3 wireless chip; U1 Ultra Wideband chip; 32 GB storage Availability of Ultra Wideband features varies by country. Apple
Location and navigation	—	Dual-frequency GPS (L1 and L5), GLONASS, Galileo, QZSS, BeiDou; compass; always-on altimeter The L5 signal helps separate signals reflected by tall buildings and trees; Apple called it the most accurate GPS of any Apple Watch at the time. Apple
Health sensors	—	Electrical heart sensor (ECG); third-generation optical heart sensor; blood oxygen sensor Availability of the ECG and blood oxygen apps varies by country. Apple
Diving and water	—	WR100 (ISO 22810); dive-ready to 40 metres (EN 13319); water temperature sensor and depth gauge; IP6X dust Apple points to the third-party Oceanic+ app for recreational scuba diving to 40 metres; the watch itself is not certified as a dive computer. Apple
Safety	—	86-decibel emergency siren; Fall and Crash Detection (high-g accelerometer up to 256 g); Emergency SOS The siren plays two distinct patterns, one signalling distress and one mimicking SOS. Apple
Low-power setting	—	Up to 60 hours Apple announced that this setting would arrive in software after launch, in autumn 2022; it extends runtime by taking some readings less often. Apple
Operating temperature	—	−20 °C to 55 °C on the wrist Apple