Ourtime Smart Bracelet Sports Fitness Wireless Bluetooth Wristband for Android IOS Smart Phones Smart wristband with 0.69 OLED touch screen shows different patterns on your phone Compatible with Android and IOS smart phones which support bluetooth 4.0. The Android phone must be 4.3 or above and the IOS must be 7.0 or above Monitor your sleep automatically and wake you up with a vibration alarm and more Rechargeable battery for long time using, low consumption.Standby time is about 20 days The size can be adjusted according to the size of your wrist. Fit 5.43''-7.68'' wrist.