1. LED bike lights USB: Can be charged at any USB port, USB cable included. You no longer need to invest in expensive and wasteful batteries. Built-in 650mAh Li-ion battery Li-polymer battery. No battery change is required. 2. Modes that can be created: Both the headlight and taillight have 4 modes: full brightness, half brightness, slow flashing, fast flashing. Set them as needed. 3. Silicone Strap: The strap is elastic enough to fit all types of bikes and can be fixed on any part of the bike, easy to loosen and close without tools. 4. Package Contents: 1 x Light Combo Kit with 1 White Headlight + 1 Red Tail Light + 2 USB Cables (28.5cm). Easy installation. The strap is easy to detach and attach. You don't need any tools. 5. Safe Driving: Light the way with the headlight and warn you with the rear light at night or when visibility is poor. IP64 waterproof for safe riding in the rain. How to charge the lights: 1. Connect the micro USB cable to the micro USB input of the bike light. 2. Plug the other end of the cable into either a wall-plugged AC adapter (not included) or a USB port on a powered computer. 3. Once the bike light is fully charged, the LED indicator will turn green. Battery Type: 650mAh Rechargeable Li-ion Battery Dimensions: 50 x 45 x 40mm. Waterproof: IPX4.