Never worry about turning your tail light on (or off) again! The new Reflex Auto tail light has both optic and; motion sensors to determine when to automatically activate the light. When darkness and motion are detected; the light turns on instantly! The combination of active and passive safety help provide even more visibility.; The "active" safety refers to our standard tail light technology, perfected over years of development. The; "passive" safety component refers to our outstanding /BS/ECE/JIS reflector design that has exceeded; highest governmental standards for many years. The 5 super-bright modes, over 180 degrees of visibility, and; various mount options will help you stand out from the crowd and guarantee you'll be noticed at night!