The Reflex Auto will automatically turn on whenever both darkness & motion are detected by the motion & light optic sensors providing the rider safety both while the light is turned on & while functioning solely as a reflector. 5 LEDs Greater than 180 degree visibility Automatically turns on / off by light & motion sensors Emits light for 50 seconds after the bike stops Built-in reflectors that meets highest government standards (USA Great Britain Europe & Japan) Opti Cube™ lens technology AAA alkaline battery x 2 5 modes Mode memory function SP-5 bracket (ø21.5-31.8mm) & Rear rack bracket Weight 82g Designed in Japan RUNTIME: Constant mode:30hrs Flashing mode:100hrs Rapid mode:60hrs Long-life mode:120hrs Pulse mode:30hrs TECHNOLOGIES: Auto Light Auto on/off controlled by motion & optical light sensors to automatically turn the light on when darkness of motion is detected. Reflector Our reflector technology exceed the highest government standards around the world. Opticube™ Our proprietary Opti Cube™ lens technology maximizes brightness for greater visibility. Side Visibility Provides visibility from the side to increase safety. All Weather Can be used in rainy weather.