The Garmin HRM Dual Heart Rate Strap will tell you your heart rate while you're working out. The heart rate strap accurately tells you your heart rate without delay. With ANT+ and Bluetooth, the HRM Dual can work together with other Garmin devices and various fitness apps. As a result, you can view your heart rate on your sports watch, smartwatch, or bike navigation system while you're working out. In addition, you can also connect the heart rate sensor to your Android, iOS, or Windows phone. The removable strap is easy to adjust between 63.5 and 132 centimeters. Garmin's heart rate strap has a replaceable battery that lasts about 3.5 years.