TICKR FIT heart rate armband uses optical heart rate technology to provide accurate heart rate and calorie burn data in the most comfortable form factor yet! Equipped with Bluetooth and ANT+ technology to seamlessly pair with fitness apps, smartphones, and GPS bike computers and watches. Worn on the forearm, the TICKR FIT heart rate monitor comes with an adjustable band that is designed for your most grueling workouts including running, cycling, fitness classes, and more. TICKR FIT has water-resistant technology and a rechargeable battery that lasts up to 30 hours. FEATURES : Bluetooth and ANT+ capabilities allow for a wireless connection to both smartphones and GPS bike computers and watches See workout data while you exercise, including vital metrics such as heart rate and calorie burn when connected to a smartphone or ANT+ device Made from advanced performance materials, TICKR FIT is designed to comfortably fit around your arm, yet fit securely during intense activity Includes a USB rechargeable battery with up to 30 hours of battery life Visual confirmation that the TICKR FIT is powered, connected, and transmitting via Bluetooth and / or ANT+ TICKR FIT comes with 2 adjustable bands (small and large size) in the box Works seamlessly with over 50 apps including Zwift, The Sufferfest, Peloton for cycling and Runkeeper and MapMyRun for running