Physi-Cal Enterprises MIO Motion Fit Petite Strapless Heart Rate Watch On-demand EKG accurate heart rate, no chest strap Multi-function activity monitor uses accelerometer technology to accurately count steps, estimate speed and distance traveled as well as calories burned Percentage of maximum heart rate Works with MIO 3500 Calorie Club program Programmable target heart rate zones with upper and lower heart rate zones, Resting heart rate: measures and displays your resting heart rate