CatEye’s Reflex Auto tail light is the only one produced with built-in reflectors that exceed US and international standards. That's a handy thing given that Vermont state law requires you to have a red rear reflector on your bike, and states that red lights can be used in addition to said reflector. The Cateye Reflex Auto provides the rider with greater than 180 degrees of visibility both while the light is turned on and while functioning solely as a reflector. And when the name says "Auto," it means it: this light will automatically turn on whenever both darkness and motion are detected by the motion and light optic sensors. No more stopping on the bike path to double check that you’ve turned your tail light on – it’s automatic!