It is a good choice for those who love sports and pursue a healthier life. Feature: Accurate heart rate monitoring helps you to achieve the best exercise state. Supports multi sport modes, compatible with both BT and ANT',  all data can be transmitted to mobile training Apps & bike computer. Large capacity and low power consumption battery support 300 hours normal use. Breathable rubber strap with adjustable elastic band, easy and comfortable to wear. IP67 waterproof allows you to enjoy running even in the rain.  Great choice for rowing, cycling, climbing, Yoga, running, training indoors or outdoors. Specification: Material: ABS ' Nylon ' Spandex Color: Black BT version: BT 4.0 Waterproof: IP67 Strap length: 60 - 95 cm / 23.6 -37.4 in Sensor Size: 13.5 * 59 * 35 mm / 0.53 * 2.3 * 1.4 in Sensor Weight: 15 g / 0.5 oz Package size: 13.6 * 10.4 * 3.8 cm / 5.4 * 4.1 * 1.5 in Package weight: 104 g / 3.7 oz Package List: 1 * Heart Rate Sensor 1 * Chest Strap 1 * User Manual