Optical heart rate sensors use light to measure blood flow in capillaries under the skin. The top of the wrist is a convenient place for a watch, but it's not the best for sensors. Wearing on the arm provides the optical sensor with an optimal amount of blood flow to collect heart rate data with accuracy equivalent to a traditional chest strap.
FEATURES
More comfortable and easier to wear than a chest strap.
Easy to adjust and remove for quick cleaning.
The latest multi-channel optical sensor for precise measurements.
Up to 3 simultaneous connections with Bluetooth enabled devices.
Wear detection automatically pairs the device for new workouts.
38 hours of continuous, accurate measurement or 80 days of standby mode on a single charge.