Description Smart Dimming: The bicycle light's built-in* optical sensor can automatically adjust the brightness according to the brightness of the surrounding environment. In strong light environments, the lights will automatically dim and in low light environments, they will automatically brighten to save power. USB Rechargeable Bike Light: No more wasting money on batteries. The light is USB rechargeable, which is convenient and ensures longer battery life. The lightweight bike light fits in your pocket or bag for easy transportation. Power Indicator: Rechargeable bicycle light with 4 grid power indicators, allowing you to easily know the remaining power and ensure timely charging. Light mode options: Smart sensor light* High light* Low light* Flash light* SOS, simple and easy-to-use bicycle light. You can change the light mode simply by pressing the power button. EASY TO INSTALL AND LIGHTWEIGHT: The bike light set can be easily installed and released without any tools. The lightweight and sturdy shell guarantees stable performance, which is very important when you are riding on difficult terrain.