SinoPro i5 Smart Bracelet Fitness Tracker Smart Wristband Bluetooth Activity Tracker with OLED Screen Pedometer Sleep Monitor Message Reminder for iPhone, Samsung and other Smartphones Smart wristband with OLED screen, show the steps, calorie, distance, time, sleep quality clearly. Make your exercise more regularly, your life more healthy. Sync data via Bluetooth with iOS and Android smart phones. iOS must be iOS 7.0 (or above) and Android 4.3 (or above) phone which with Bluetooth 4.1. Insert the USB stick of the host device into wrist band, then lock the clasp (as shown in the figure), all wrist band are free size, you can adjust the clasp upon the size of your wrist. Host comes with a standard USB port, special design to charge through connecting PC and mobile driver. Sync sport data with apple and android device: Go to App store or play store, download this APK: "Zeroner" and install it.