Features: Premium heart rate strap transmits real-time heart rate data over ANT+(R) connectivity and Bluetooth(R) Low Energy technology for optimal training indoors, outdoors, and online Consistently receive your accurate heart rate on your Garmin(R) device, in online training apps such as Zwift, or even the compatible fitness equipment in your favorite class at the gym Soft strap is adjustable for a more comfortable fit Battery lasts up to 3.5 years Strap is machine washable after removing the heart module