Excelvan Wrist Fitness Trackers Bluetooth 4.0 Data Sync/Pedometer/Calorie Monitor/Sleep Monitor/Silent Vibration Alarm This Smart Bracelet can diaplay the time, steps, distance and calorie clearly. Let you know your sports data right now Snyc Sports Data, Share with Friends;When bluetooth paired, it can automatically sync your data to other devices, such as iphone 4S,5,5S, ipod touch5, etc. (OS must be IOS 6.0 or later); Samsung S4, Note 3, etc. (OS must be Android 4.3 or later). Challenge and compete with your friends! Make progress with your friends together! It gives you real-time assessment of your exercise throughout the day. It is your best activity companion! Silent Vibration Mode Built-in silent vibration mode, a silent remind alarm that gently vibrates to remind you at your desired time without disturbing your partner. -Light Weight It is just 20 g! So when you wear it, you even won't feel it! You can work and exercise ordinarily.