Compatibility: Android OS 4.4+ or iPhone 5 with iOS 8.2+; Connectivity: Bluetooth Smart Enabled with 4.1 Low Energy; Battery Life: Up to 4 months Based on usage; Battery Type: CR1632</br>Stay connected with the DieselOn Track cuff, featuring a wide brown-and-black leather strap with a glow-through illum diffuser notification panel.</br>Track your activity using the light-up logo diffuser, so you'll know the second you've reached goal. The sleep tracker will help you recount your light, restful and awake time.</br>Band Circumference: 15.5cm - 19.4cm; Sensors: Accelerometer; Storage: Stores Up to 2 Weeks of Data; Included Accessories: Caseback Tool</br></br>Product Description</br></br>DieselOn Track</br><br/>http://www.amazon.com/gp/product/B01LXI4DTZ