【Compatible Sensor】: The heart rate monitor replacement soft belt is compatible with MyZone Mz-1 Mz-3. If there is any compatibility issues, kindly contact us on the order page and we will reply you within 24 hours. 【Adjustable Chest Size】: Wearable size from 25.6" to 37.4".This chest strap can be worn in sizes from M to XXL, suitable for people of various body types. 【Elastic Material】: Silicone +Fiber. The high-quality fabric chest strap is comfort to wear, lightable and the length can be adjustable according to your size. 【High Quality, Top Durable】: The chest strap has a waterproof function, which can enhance the signal in the electrode area and better connect the sensor, which can pick up your heart rate date quickly, providing stable connection and accurate data to help you exercise better. 【How to Use】: Moisten the plastic electrode areas on the the reverse side of the strap. The electrode area needs to be tightly pressed against the skin, and check if the connector is in the correct position. 1. The heart rate monitor replacement adjustable strap can work with MyZone Mz-1 Mz-3 ( not fit for myzone switch). 2. This chest belt is also more comfortable, soft, and elastic than MyZone's chest strap, with a higher fit and better compatibility with your sensors. When you exercise, you may forget its existence, which can help you exercise better. 3. A good replacement strap can extend the service life of your sensor. Our replacement strap uses the latest technology and materials, providing you with a higher quality choice. 4. Suitable for various outdoor sport, such as swimming, running, cycling, rock climbing, mountaineering, hiking, fitness, etc.