These are sticky-backed "slap stickers" that were released to promote Tony Hawk's Pro Skater 3 + 4. This one is approximately 5.5"

They were put up on a wall in Venice Beach for people to take (see the video posted).

There is no backing to peel off on these, they are supposed to by re-usable, able to just slap on anything, peel off and put on something else. They appear to be made of a thick vinyl material.

I have several different designs from the wall (see other listings), will combine shipping

NOTE - These were pulled off the poster wall, these sticky back  slap stickers are not like real sticker adhesive.