Make every beat count with Charge HR a high-performance wristband with automatic, continuous heart rate and activity tracking right on your wrist. See heart rate all day and during workouts to get more accurate calorie burn, reach your target workout intensity and maximize training time. Track steps, distance, floors climbed and sleep quality and more, and stay connected with Caller ID and time of day on display. Charge HR also wirelessly syncs to your smartphone. Fits wrist size 6.2" to 7.6" round.