The Reflex Auto will automatically turn on whenever both darkness and motion are detected by the motion and light optic sensors, providing the rider safety both while the light is turned on and while functioning solely as a reflector.Key Features:5 LEDs,Greater than 180 degree visibility,Automatically turns on / off by light and motion sensors,Emits light for 50 seconds after the bike stops,Built-in reflectors that meets highest government standards (USA, Great Britain, Europe and Japan),OptiCube™ lens technology,AAA alkaline battery x 2,5 modes,Mode memory function,SP-5 bracket (ø21.5-31.8mm) and 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 OptiCube™ 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..