CooSpo HW706 Heart Rate Monitor Armband Brand new, unopened. [Optical Heart Rate Technology, LED Light] Uses an optical system to accurately measure and monitor data. You can check if the sensor is already working with the LED light. Suitable for exercises such as cycling, running, and fitness. [Support for Multiple Apps] Can connect to Wahoo, Runkeeper, Zwift, Sports Tracker, and many other apps. [Bluetooth and ANT+], compatible with Bluetooth 4.0 and ANT+, smartphones, tablets, GPS watches, fitness equipment, etc. [Convenient and Fast] Uses USB charging. No need to replace the battery. Working time is 20 hours, waterproof IP67.