reflector
A shiny red or yellow light that reflects off of a peice of plastic? (magical material) that helps cars and or pedestrians notice whats up. very helpful to bicyclist and one hell of an invention. props to the brilliant inventer. :
Example:
Dude thank god we have reflectors on our bikes. That car totally would have not seen us. We coulda ate sh!t.
Dude thank god we have reflectors on our bikes. That car totally would have not seen us. We coulda ate sh!t.