Feature:\u00A1\u00EF[Waterproof] Bicycle waterproof taillights can prevent water from splashing from all angles. A USB cable is included, which can be charged from your computer, charger, power bank or any other device with a USB port. After charging for 3 hours, the taillight can be used for 15 days.\u00A1\u00EF[Remote control effective distance] The maximum remote control distance of the remote control is 50 m. You can control all functions by pressing the function button on the doorbell. In this way, you can easily find your bike in the dark by turning the lights on or off.\u00A1\u00EF[Multifunctional] exquisite design, can be used as tail light and helmet light. Whether in the city or on rural roads, visibility and safety can be improved at any time of the day.\u00A1\u00EF[Alarm System] The alarm is up to 120 decibels, and the bicycle safety siren emits a loud sound to attract peoples attention. It can effectively stop thieves loudly, and can also be used as a bright taillight, smart remote alarm and electric bell.\u00A1\u00EF[Easy to carry] includes an adjustable saddle, so that the rear light of the bicycle can be flexibly and quickly installed on or removed from the bicycle, seatpost and seat tube bracket. Unscrew the bracket cover to facilitate charging.