Excelvan SW2-B Smart Healthy Bracelet Bluetooth V4.0 Wristband with Pedometer, Sleep Monitoring, Tracking Caloria Compatible with Android Phone This smart bracelet with OLED screen clearly displays health parameters including steps, calories, distance, time and sleep quality. With silicone adjustable wristband and light weight feature, you can wear it comfortably, such as running, climbing. When you do exercise, it can record your sports data. When you sleep, it can monitor your sleep. All these data can be synchronized and analyzed on your smart phone. for Andriod Phone (OS must be 4.3 or above and Bluetooth must be V4.0) and for (ios must be 7.0 or above and Bluetooth must be V4.0; but ios 8.0 can't use ) Wristband Material: Silicone ; Screen:OLED ; Bluetooth:V4.0