Material: Nylon, Spandex Size: The size is one meter in length, and the distance between the two holes is 45mm. Compatible: Support 5MM center distance heart rate belt universal Bluetooth transmittePackage List 1*Chest Strap Chest strap only, heart rate sensor transmitter not included. 11. Easy to use and clean: Use the same snap connection method. The sensor transmitter must be removed and the soft straps must be hand washed as often as needed. 22. Compatible with heart rate sensor: Support 5MM center distance heart rate belt with universal Bluetooth transmitter. 33. Adjustable size: the size is one meter in length, and the distance between the two holes is 45mm. 44. Comfortable and excellent workmanship: The chest strap is made of nylon and spandex material to fit your skin tightly. The soft fabric and adaptive electrodes make it extremely sensitive to your heart's electrical signals. 55.