The XZ831 heart rate monitor arm band can adjust your exercise intensity in real time according to your heart rate, scientifically and effectively improve exercise efficiency. The sensor is worn on the band of swimming goggles, and the ergonomic design is close to your temple to give you the feeling of wearing nothing, and real-time data transmission experience comfortable heart rate tracking. Support Bluetooth and ANT+ dual protocol wireless transmission compatible with iOS and Android smart devices, easily adapt to a variety of popular apps on the market, built-in high-precision optical sensor, real-time monitoring of heart rate changes. Real-time heart rate monitoring allows you to adjust the intensity of your exercise in time, making your exercise more scientific and effective.