Features: Bicycle lock and tail light in one. Comes with a mounting bracket that can be installed under the bicycle saddle for easy portability. The bicycle lock can be used as a tail light at night, acting as a warning light and improving safety during night riding. 4 lighting modes: The bicycle tail light has 4 modes: White password light, constant red light (6 hours), constant dim red light (10 hours), and fast flashing red light (7 hours). Click the power button to switch between modes. Turn on the password light at night for easier unlocking. 5-digit password: The original password is 00000. The bicycle lock is very secure and resets to a 5-digit code. No key is needed, so you don't have to worry about losing or forgetting it. 100,000 preset password combinations, high security and strong anti-theft effect. USB charging: Equipped with a USB charging cable, it can be charged from any device with a USB port. Charging is fast and easy, no need to change the battery. A full charge can last 6 to 10 hours and provides a long standby time. Robust and durable: The lock body is encapsulated in polyvinyl chloride on the outside without damaging the frame or wheel assembly. The 12 mm wide lock body is safe and anti-theft. The bicycle lock is 120 cm long, and when not in use, the cable lock can be rolled up and attached to the bracket for easy portability.