*** CR1620 3V Battery Not Included *** Product description Colour Name:Silver Tired of losing your keys, Wallet or phone? make misplacing your belongings a thing of the past with TrackR Bravo! it's a Bluetooth device you can attach to any important item. Use the TrackR app to locate it in seconds. Quickly ring your keys or press the button on the TrackR Bravo to make your phone ring -even on silent. Keys fell out of your pocket? crowd locate will automatically start searching for them. When another TrackR app user is within Bluetooth range of your lost item, you'll receive an anonymous location update. Users help each other find over a million items every day.