1. Bluetooth 4.0 low energy technology synchronizes the mobile APP application, records heartbeat data in real time, and detects heartbeat status. 2. The data is accurate, providing the highest, average heart rate, exercise time, and other data. 3. Accurately monitor the exercise heart rate and calorie consumption, continue to observe changes in heart rate during exercise, help to understand the state of physical fitness, adjust training methods in a timely manner to improve cardiorespiratory endurance. Smart Bluetooth 4.0 Heart Rate Monitor Sensor Chest Strap Fitness Equipment for iOS Android Phone s: 1. Bluetooth 4.0 low-power transmission, with the use of APP to achieve wireless data transmission 2. Chest strap length adjustment range: 70-120cm/27.6-47.2inch 3. Battery 1 CR2032, about 700 hours 4. Waterproof, sweatproof, easy to clean 5. Equipment requirements: for Amdroid 4.4 and above and iOS devices with Bluetooth 4.0 support. Functions: 1. Detect your heart rate in real time. 2. the achievement of the of the exercise and provide data-based exercise results. 3. The effect of losing weight and strengthening the body will be achieved with half the effort. 4. Determine whether your exercise exceeds the heart and body load to avoid accidents. 5. Monitor exercise intensity, prevent under- or excessive exercise, reduce muscle strain and soreness. 6. Accompany you and remind you to exercise. 7. Monitor and make your workouts more visible. 8. Applicable scenes: Cycling, running : Colour:Black Material:Rubber+plastic Package Contents: 1 * Heart rate chest band(With English manual) Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.