These "Super Eyes" decals are roughly 6.5" Wide, so you can cut them in half and place them on different areas on the back of your helmet.
Reflective vinyl is the highest performance 3M material on the market today. This material also has a coat of UV Laminate over the top, which extends the outdoor life to roughly 10 plus years if taken care of properly. This material shines bright when the light or flash hit's it. It's the same material you see on most school buses, police cars, firetrucks, etc.