POSMA DB1 BLE4.0 Cycling Computer Speedometer Odometer, Support GPS by Smartphone Integration iPhone and Android (BHR20 Heart Rate Monitor and BCB20 Speed/Cadence Sensor Bundle Option Available) In the box: cycling computer, holder, fixing pad, cable tie x4, button battery and quick start guide. Integrated with SmartPhone Perfectly: DB1 wirelessly receives the real-time data from your SmartPhone. You can monitor your heart rate, speed, cadence, gradient, and more, simply from DB1. Meanwhile, the SmartPhone records the comprehensive and detailed data that offers you the complete report after finishing the cycling. SmartPhone Connect Chooseable: Even if you do not like to ride with a SmartPhone, you can still use DB1 independently. DB1 supports the set-up training program by itself. You can get a comprehensive workout data by pairing with a heart rate strap and a speed/cadence sensor. Save Battery Life: DB1 captures distance data from GPS on a SmartPhone or a speed/cadence sensor itself. That makes the battery life for DB1 up to 800 hours. Moreover, DB1 uses a long-lasting, replaceable coin-cell battery with no need for extra cables for recharging. Easy to Use: Mount with a turn, start with a button. Anytime you would like to start it, just press and ride. Scrolling between the display functions with the single button design, no matter which gloves you are wearing. Simplified but Not Simple: DB1 is designed to be urban and modern looking. You can see the minimal design elements such as the small nearly square shape, one top button design, and large screen on DB1.