WaterproofSmart bicycle taillight uses the latest technology and has waterproof function. We have designed this light to make it work longer, so the brightness will automatically be reduced to 70% during the day. Always keep you and your companions safe.Auto on/off5 light modes to choose from: Fast flash mode, slow flash mode, meteor mode, Tai Chi mode, breathing mode. In low light, the smart bicycle taillight will automatically detect and turn on to remind the cyclist and car driver behind.Manual or automaticIn manual mode, the lights are turned on and off manually, and the bicycle lights have a brake induction function. If you cycle at night, you can set manual mode so that it is always on. In automatic mode, the light sensor automatically starts and stops, and when the bicycle moves, starts, stops or brakes, the light will be detected.High visibility and safety215m visible, 20 lumens, ultra-brightness and wide-angle view provide extremely bright lighting at the rear. It illuminates the road so that you can easily be recognized by others. It guarantees greater safety and helps you stay away from many accidents. The bicycle taillight has a built-in high-speed sensor and a deep algorithm that can quickly recognize the taillight even with light braking.USB rechargeableThe smart bicycle brake light automatically turns off when it detects no movement after 30 seconds. When you touch it or detect that the bicycle is moving, the light will automatically turn on. With battery reminder function.