Fitness Tracker Smart Bracelet,Vcall I5 Waterproof Bluetooth Activity Tracker Smart Band Wristband Fitness Bracelet with OLED Display Sports Pedometer Health Sleep Monitor(Black) Steps taken at the very beginning will not be displayed till your steps are getting steady. As a standalone fitness tracker, I5 tracks your steps, calorie consumptions, sleep status and walking distance even without a phone Do remember to clean the fitness tracker if there are any accidental water or oil contacts. Though being waterproof, swimming with the bracelet on is not recommended. Get a more complicated nickname if you can not register a new account on sync app - Zeroner Great health gadget for kids, the youth, men or women. Also fits for large wrist customers thanks to the adjustable band design. Kindly know that the data will be cleared automatically at 00:00 everyday Get text message and some other social apps' notifications when Bluetooth connection is enabled, making synchronizing data to your iOS/Android devices a quite easy thing Compatible with Android & iOS smart phones. Such as iPhone 4s/5/5c/6/6s, Note 4 etc. Some phone models like MEIZU may not well be compatible with this tracker as app restarting or exiting may happen.Your OS should be Android 4.4/iOS 7.0 or a higher OS powered and supports Bluetooth 4.0