These stair treads are beautiful! They were smaller than I expected but it doesn’t bother me or mess with the function. The bottom is not an adhesive - it’s like a weird mix between a no skidslightly sticky back But it doesn’t leave ANY residue! I was a little skeptical at how unsticky it was but they really don’t move and no one has tripped at all and these steps are used by 4 kids  2 adults daily. And they haven’t damaged our hardwoods at all. Would purchase again if you’re looking for something to stop slips and add some color!