Display Size(Inch): 0.91inch - Capacity(mAh): 65mAh - Stand-by time: 140H - Smart Bracelet is compatible with many phones and pads equipped with Bluetooth 4.0 and running Android 4.3 or later and iOS 7.0 or later: IPHONE 4S/5/5S/5C IPAD 3 IPAD Mini IPAD Air IPOD touch 5 (iOS7.0 or later) Samsung S3/S4 /Note3 HTC One Nexus4/5/7 etc - Track Sleep including total hours time to fall asleep number of wake ups - Track Activity including steps distance calories burned active vs. idle time Wakes you (and not your partner) with a silent alarm - Set goals view progress and earn badges - Syncs automatically to your smart phones and tablets via Bluetooth 4.0 BT connection: 1. Turn on the Bluetooth of your phone/pad and run the Smart Bracelet app; 2. Enter the Sync interface turn on Bluetooth connect; 3. Click the all-purpose button lighting the OLED screen the app will connect with the bracelet automatically. 4 .First of all click Sync the time on the app to sync the time of the bracelet. You can sync the target sports and sleep data the same way. The smart bracelet stores your exercise data and the app analyze those data. Turn on your phone or pad scan the dimension barcode to download and install the smart bracelet app