Product Type: Zeblaze Btalk 2 Lite Smart Watch With Calling Function Brand Name: Zeblaze Model No: Btalk 2 Lite It has Bluetooth Calling Function It has also all message Notification Function Display type: IPS HD Touch Screen Display size: 1.39" Large IPS Color Display Display resolution: 360*360 pixels Battery capacity: 220 mAh Battery type: Li-Pol Battery For Long Life Typical usage modes: up to 14 days Heavy usage modes: up to 7 days Continuous voice calling: 325 mins Charging time: 1.5 hours It has Wrist Heart Rate Monitor, Pulse Ox Blood Oxygen Saturation Monitor, Proximity sensor, Accelerometer These all sensors are for reference only not for medically usages. Bluetooth version: BLE 5.2 Latest Wrist Band Material: Durable and comfortable fluoroelastomer strap Width: 22 mm, compatible with standard 22 mm quick-release watch bands Wrist Circumference: 145-220 mm Smartphone Compatibility: Android 4.4 or iOS 8.0 and above It has 6 months brand warranty