Function: record function when riding speed step speed time function of calories. Bluetooth 4.0 low energy consumption suitable for existing APP. Combined with the telephone clock GPS music playback. Take pictures and heart rate function; Can specify cycling plan; Transmission distance: 3m. Speed tracking and heart rate simple user interfaceintuitive clock display can let users understand real-time cycling speed in the process of cycling bluetooth bike meter will record the route and time go by and through bluetooth and real-time transmission of riding speed of step speed and so on a mobile phone relative to the traditional bicycle use more convenient more comprehensive data.