Sync Burn is the perfect, wireless fitness partner. It tracks your every move, provides you with ECG accurate heart rate data and calculates a truer calorie count. With a simple press of a button, it wirelessly uploads all your data to the MapMyFittness app, where you can view, track and share your fitness progress. Water resistant to 30m. Syncs with iPhone 4S and 5. Also has a digital time and date display and a stopwatch. Wrist monitor. Batteries required 1 x C (included).