Vktech&reg; OLED Bluetooth 4.0 Sync Healthy Smart Bracelet Sport Fitness Activity Tracker for iPhone Android Bluetooth Sync Healthy Smart Bracelet Sport Fitness Tracker for Android iPhone Double bright screen, Pedometer, Distance course, Stopwatch, Date, Stopwatch, Sleep monitoring, Calorie burns, Week LED display,Bluetooth version: 4.0 + EDR,Battery capacity: 80mAh Bluetooth version: 4.0 + EDR ,Standby time: 36 hours, Case material: Rubber/Silicon/Silica Gel