Features: You must connect phone through BT before use. For IOS 7.0 Android 4.0 BT 3.0 above smartphones. Pedometer: Helps daily detection. Sleep Monitor: Ensure that your healthy sleep. Heart Rate Monitor: Monitor your heart rate. Anti-lost Reminder: Endure your phone safe. It also support call remind, Information Push, SUOTA Function, etc. As a smartphone companion and sports partner, it is the best product for yourself and your friends. Perfect design, convenient to take along. Note: Before you use it, you must download APP. Item color displayed in photos may be showing slightly different on your computer monitor since monitors are not calibrated same. Before you use it, you must confirm the size of strap suitable to you or not.