The Green Atom Symbol Reflective Decal comes in 17 size options from 2" - 18" in diameter. It can be the perfect safety detail on the back of a motorcycle helmet or a bold statement on your car. But you can apply it to any smooth hard surface like plastic, metal or glass. This Reflective Atomic Symbol is cut from Automotive Grade, Genuine 3M Retro Reflective Safety Vinyl. This is the same reflective decal material used on police cars and fire trucks. It looks like a regular decal in the daylight, but at night it glows under flashlights and headlights.