USB Charging Light - Built-in 220mAh rechargeable lithium battery, which can be charged from any USB port. The waterproof rating is IPX4- to prevent splashing water from any angle. Super bright, with 4 modes - full brightness/half brightness/fast flashing/slow flashing, it has four lighting modes that you can easily switch between. Safety when riding: The tail lights emit a striking wide-angle beam, which can be seen several blocks away without you having to worry about being hit by others. Whether you are running, walking the dog, cycling, skateboarding or hiking, these safety lights will keep you safe. Easy to install - With a convenient one-click disassembly button, you only need to slide the light to turn on and off the mount without disassembling the entire installation bracket. The silicone strap design of the tail lights has four openings, which can fit tightly on most sizes of handlebars and seatposts.