This heart rate monitor chest strap is an indispensable part of the heart rate monitor work as ANt+/Bluetooth,5.3K.... It will detect and send your real-time heart rate to the receiving terminal accurately. 1. Specifications: A).Space between two snap buttons: 45 mm. B).Belt length: M:90-115cm / 35.4"45.2". C).Material: Nylon + Spandex. D).Color: Black,Grey,ORANGE,Red,Pink,Light Blue, Sapphire. 2. Features: Soft elastic strap provides a comfortable fit. Easy to use, clean, durable, highly efficient and stable. Soft fabrics and adaptive electrodes make it extremely sensitive to your heart's electrical signals. 3. Compatible with the most of the mainstream heart rate sensors(The Space about 45mm). Such as Polar H7, Wahoo, Garmin,Timex,Peloton,Coospo. 4. Instruction: 1).Wet the sensors on the inside of the strap. 2).Attach the monitor(not include) to the strap. 3).Attach the strap around your chest. 4).Make sure the monitor sits above the base of your chest bone. 5).Package Included: 1 x Chest Belt Strap (only strap not including transmitter)