USB Charging Light - Built-in 330mAh rechargeable lithium battery can be charged from any USB port. Waterproof rating is IPX4 - protected against splashing water from any angle. Super bright 4 modes - full brightness/half brightness/fast flash/slow flash, it has four light modes that you can switch easily. Get riding safety: The taillights emit an eye-catching wide-angle beam that can be seen from the block without worrying about being run over by others. Whether you're running, walking the dog, biking, skateboarding or hiking, these safety lights will keep you safe. EASY TO INSTALL - With the convenient one-touch removal button, you can simply slide the light on the base without removing the entire mounting bracket. The silicone straps for the taillights are designed with four openings for a snug fit on most handlebar and seatpost sizes.Note, because there may be color and size differences between the light effect photos and the actual product, please allow 1-2 cm errorQuantity: 1 set (2 pieces) bicycle tail lightSize: 7*2*1.7 cmColor: red red light