: Quantity: 1set Color: black Smart Light Set Sensing Function: This bike light set include motion sensor and light sensor. When no motion is detected after 45 seconds, it will turn off automatically. Once the bicycle movement is touched or detected, the light will turn on automatically. In addition, when you ride in the sun, the tail lights will automatically turn off due to the light sensor. Five Mode Switches: Steady on / fast flashing / slow flashing / rhythmic flashing / ecological flashing. The smart bicycle brake light can sense the bicycle brake, and the bicycle tail light immediately lights up the brightest red light for 3 seconds to remind other road users. This feature applies to all light modes. USB Charging And Extra Long Standby: The rear lamp can work for up to 23 hours after full charging (different battery life in different modes). It can be easily charged from a computer, charger, or power pack and switch from these modes by simply clicking a button. Easy To Install And Remove: Saddle mounting bracket and adjustable silicon tape are provided to install on the saddle rail or seat column. Without additional tools, it can be easily unscrewed from the mounting cover for charging. Premium Performance: Made of alloy shell, brake tail lamp has good touch and excellent appearance. Waterproof / dustproof, shockproof, suitable for any harsh working environment. The best choice for bicycles.