There are several different MIO watch models and each model has a different set of features designed to enhance your lifestyle activity of choice.  To view a complete listing of MIO watches click here.  All MIO watches take your ECG accurate heart rate without a chest strap and all MIO watches display percent of maximum heart rate. Some MIO watches use your personal data to calculate your calorie burn during a workout while other also allow you to manage your weight with MIO's patented calorie intake prgram.  All MIO watches feature interchangeable color bands.