The optical heart rate sensors use light to measure blood flow in the capillaries located under the skin. The top of the wrist is a convenient place for a watch, but it is not the best for sensors. Wearing it on the arm provides the optical sensor with an optimal amount of blood flow to collect heart rate data with accuracy equivalent to that of a traditional chest strap.

• More comfortable and easier to wear than a chest strap.
• Easy to adjust and remove for quick cleaning.
• The latest multichannel optical sensor for precise measurements.
• Up to 3 simultaneous connections with Bluetooth compatible devices.
• The wear detection allows for automatic pairing of the device for new workouts.
• 38 hours of continuous and precise measurement or 80 days in standby mode on a single charge.
• Rechargeable using a magnetic USB charging cable.