Light and Motion Tail Light has a Smart sensor senses motion,automatically turns on when inserted into mount. Auto-off when bike is parked or light is removed from mount Made with bio-renewable material waterproof to 1 meter (IP67 Rated) Innovative amber side lighting increases visibility at intersections Mount or remove from bike in seconds with a simple, secure 1/4 turn lock Direct USB Charging Without Cables (Fully charges in 2 hours)