Samsung Galaxy Watch8 44 mm Bluetooth (SM-L330) / Amazfit T-Rex 3 (48 mm)

Always On Display keeps the watch face visible but shortens battery life; when off, the screen wakes on wrist raise.

There is also a night display mode.

Sapphire crystal resists scratches better than ordinary glass. The 8.6 mm thickness excludes the sensor bump on the back.

32 GB of storage is enough to keep music and apps on the watch for phone-free runs.

The watch charges only wirelessly; it must align with Samsung’s charging puck, and some wireless chargers may not sit flat because of the band.

The electrical heart signal enables ECG and bioelectrical impedance enables body composition readings. ECG and blood pressure need a Samsung phone and country approval.

The watch offers an altitude assistant, storm alerts, compass, sunrise/sunset and tide information, and prompts for blood-oxygen readings at high altitude.

Antioxidant Index is measured by holding a fingertip on the sensor for about five seconds; Vascular Load needs the watch to be worn to sleep on at least 3 of the last 14 days. These are wellness indicators, not medical diagnoses.

The L5 band helps reduce route drift caused by reflections among tall buildings and trees.

On the Bluetooth model calls and notifications work while connected to the phone; NFC contactless payments depend on country and bank.

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.

5ATM means water resistance suitable for swimming, not diving or high-speed water sports. MIL-STD-810H refers to selected environmental tests from the military standard and is no guarantee against impacts.

Gemini can act in Samsung Health, Calendar and Clock via voice; availability varies by device, language and country.

It cannot be used with an iPhone.

The 22 mm strap is a standard width and can be swapped.

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.

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.

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.

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.