Hardware Brand: Amazfit Model: Stratos Available Color: Black Chip: Dual core, 1.2GHz Memory: 512MB + 4GB OS: WOS 2.0 Compacibility: Android 4.4, or above; IOS 9.0 or above phones with BT4.0 Waterproof rating: 5ATM Functions Firstbeat Health Data Tracker : Maximum oxygen uptake(VO2max), Exercise load(TD), Exercise effect(TE), Recovery Time. Other functions: Swimming Mode, Call reminder, Info push, GPS+Glonass, Bluetooth music, Alarm, Remote Control of Mijia Smart Home Devices. Sensor: PPG heart rate sensor, acceleration sensor, gyroscope, geomagnetic sensor, light sensor Motor: Support App: Amazfit 2.0 or Mi Fit Alert type: Vibration Connection Bluetooth version: V4.0BLE Display Screen type: 1.34 inch, capacitive Resolution: 320*320 pixel Operating method: Touch screen Battery Battery type: Lithium polymer Battery capacity: 280mAh Running mode: About 5 days GPS+running mode: About 35 hours Apperance Dial material: 2.5D Screen Case material: Ceramics Band width: 22 mm Package Contents 1 x Huami Amazfit Smart Watch, 1 x USB Cable, 1 x Charging Dock, 1 x User Manual