The Amazfit T-Rex Ultra is a rugged smartwatch with a 1.39-inch AMOLED display, a 316L stainless steel case, and military-grade durability. Key specs include 10 ATM water resistance for freediving, dual-band GPS with support for six satellite systems, and up to 20 days of battery life in typical usage. It is equipped with BioTracker PPG and other sensors for health monitoring, 160+ sports modes, and the Zepp OS. 

• Size: 1.39-inch AMOLED
• Resolution:
  454×454

  pixels (~326 ppi)

• Brightness: 1,000 nits peak brightness
• Features: Always-on Display 

• Build: 316L stainless steel case with a polymer alloy middle frame and a patented mud-resistant bridge and buttons
• Water Resistance: 10 ATM, suitable for freediving up to 30 meters
• Durability: Passes 15 military-grade tests (MIL-STD 810)
• Weight: 89g (with strap)
• Dimensions: $47.3 \times 47.3 \times 13.45$mm
• Colors: Abyss Black, Sahara 

• Sensors: BioTracker™ PPG biometric sensor, acceleration sensor, gyroscope, geomagnetic sensor, barometric altimeter, and ambient light sensor
• Positioning: Dual-band (L1 and L5) and 6 satellite positioning systems (GPS, GLONASS, Galileo, BDS, QZSS, NavIC) 

• Capacity: 500 mAh (rated value)
• Typical Usage: Up to 20 days
• Endurance GPS Mode: Up to 80 hours 

• Connectivity: Bluetooth 5.0, Wi-Fi 2.4GHz
• Supported Devices: Android 7.0 and above, iOS 14.0 and above
• App: Zepp App