Technical specications: 0.91 OLED display (2.3cm) with 128x32 pixels resolution Bluetooth Low Engerie V4.0 with max. 10m distance Supports RTC (Real Time Clock) & time sychronization Built-in rechargeable 55mAh lithium-ion polymer battery 3.7V Battery charging time ~2 hours Battery working time ~3 days (depend on the use) / Standby time ~10 days Charging via charging adapter with Micro USB port IP67: dust proof & protection against temporary immersion up to a maximum depth of 1m Weight / Dimensions: 18g / (L) 4.43 x (W) 1.79 x (H) 0.93cm Wristband strap: (L) 15.5–21.5cm x (W) 1.83cm Compatibility: Apple iOS Devices: Supports iOS device with 4.0 BLE, iOS 7.0 and above. Android Devices: Supports almost all Android devices with 4.0 BLE, Android system 4.3 and above. Gyártó: Technaxx