about this project USB Rechargeable Lights: USB rechargeable front and rear lights, built-in 2000mAh rechargeable lithium battery for front lights, built-in 330mAh rechargeable lithium battery for tail lights. Super Bright with 4 Modes: The headlights and taillights have a one-button switch, which provides four different lighting modes according to your preference. Including full brightness, half brightness, fast flash, slow flash. EASY TO INSTALL/QUICK RELEASE: The headlight comes with a mounting bracket for easy attachment to the handlebar. The silicone mounting straps for headlights and taillights are designed with four openings to fit snugly on most sizes of seatposts. Both headlights and taillights can be easily released and fixed without any tools. MULTI-PURPOSE: This bike light will bring you a visibility light for extra safety and protection in bad weather. The bike light alone can also be used as an emergency flashlight, flashlight, helmet headlight for biking, camping, walking or other night work.