Bluetooth Smart Bracelet Wearable Device Sync Fitness Tracker/Heart Rate/Blood Pressure/Emotional Status/Fatigue Level for Samsung HTC Huawei Xiaomi Android Smartphone and IOS Iphone(black) Adoption of new material, and crown radian design make it comfortable to wear at day or night. By measuring the heart beats spats,monitoring the number of calories,real time control of the heart movement exercise goals. At night, it tracks your sleep cycle. Let you know how long and how good you sleep, to help you improve your sleep quality. Detection of your physical parameters including blood pressure, pulse, emotion and tiredness indexes, offering you health advice. Suitable to all occasions and No GPS function. Upgrade the app to latest version for better functionality.