Mio Alpha 2 Heart Rate Watch + Activity Tracker Get accurate wrist-based heart rate during exercise. Track workouts plus all day activity, including steps, calories and distance. Store up to 25 hours of workout data. Sync wirelessly via Bluetooth Smart (4.0) to popular fitness apps. Water resistant up to 30m (3 ATM / 100 ft.). Compatible with Mio PAI App (Personal Activity Intelligence). Have questions about your Mio? Contact Mio Global at 1-877-770-1116 (Mon-Fri: 9am to 5pm PST) and kindly refer to the user manual for instructions and troubleshooting. To add all day activity tracking, easily update your firmware via Mio GO app.