【Compatibility】 Designed for MYZONE MZ-SWITCH (Not Compatible with MZ-3 & MZ-1) for seamless replacement. 【Adjustable and Comfortable Fit】 The wearable size is larger than the adjustable size, stretching more than 1.2 times. The Small size measures 19.7-25.6" inch /55-70 cm. Crafted from a blend of Nylon and Spandex, the chest strap adheres closely to your skin. Soft fabrics and adaptive electrodes ensure precise tracking of your heart's electrical signals. 【Easy to Use and Clean】Features the same snap attachment method for easy application. Remember to remove the sensor transmitter before cleaning. Hand wash the soft strap and allow it to air dry naturally. 【Name and Date Tag】 It is simple to recognize and locate your own heart rate band while taking part in group activities or competitions without making mistakes. Alternatively, you can just jot down dates, results, etc. 【Note】 The package only includes a belt strap. Please kindly check your heart rate monitor model and wearing size before placing an order. The heart rate monitor chest strap is an adjustable replacement strap fits for MYZONE MZ-3 &MZ-1; 1. Specifications: A).Belt length Small: Adjustable Wearing size between S:21.5~27.6" inch /55~70 cm B).Material: Nylon + Spandex. C).Color:Red& Black; 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. Instruction： 1).Wet the sensors on the inside of the strap. 2).Attach your heart rate monitor transmitter 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)