Mio FUSE Heart Rate, Sleep + Activity Tracker Get accurate wrist-based heart rate during exercise. Track all day activity, including sleep, steps, calories, distance, pace & goal. Tracking sleep requires a simple software update. Sync wirelessly via Bluetooth Smart (4.0) to popular fitness apps. Works exclusively with Mio PAI app (Personal Activity Intelligence). Water resistant up to 30m (3 ATM / 100 ft.) To add sleep tracking, easily update your firmware via Mio GO app. For Mio product support, please contact 1-877-770-1116 (Mon-Fri: 9am to 5pm PST). Please refer user manual attached below for instructions and troubleshooting steps.