LUOOV Big Black Heart Rate Smart Activity Tracker for Android and IOS 1.Compatibility: requires Android 4.3 or above, iOS 7.0 or above,Bluetooth 4.0. Download APP "HPlus Watch" from Apple Store or Google Play for free 2.Large OLED screen allow you to check time, date, steps, calories, working distance, message, Heart rate quality easily 3.Snyc Data: When bluetooth paired, you can sync your data to Andriod/IOS phone. It gives you real-time assessment of your exercise throughout the day 4.Functions:Time Display,Heart Rate Monitoring, Sleep Quality,Task Remind,Coming call,Step Watch and Step ,Calories Burned,Distance 5.We promise: 30 days return and exchange, 12 month warrantly. So please be secure to purchase 6. Not Waterproof