Easy to wear, easy to use - ECG accurate heart rate WITHOUT a chest strap.This is a great watch if you are a casual exerciser interested in improving your heart health. MIO Breeze is an easy-to-use, ECG accurate heart rate monitor that works without a chest strap. Built with top-of-the-line materials, Breeze boasts our latest styling and feature-set. MIO Breeze features: Easy-to-wear, easy to use, ECG accurate readings WITHOUT a chest strap. Exercise safely and effectively with visual exertion level indicators and % of max HR. Two (2) exercise timers. Full-featured sports watch with date/time/calendar, alarm, chime, backlit display with 30 m water resistance. Battery hatch so you won 't be without your MIO for more than a few minutes!