I bought a chair with wheels and a floor since I have I bought these rollers to protect it. A little disappointed by the wheels because they are not as "soft" as I wanted. It's still better than the original hard plastic. No problem for mounting. For cons, I do not like the fact they lock when you get up from the chair. So, it often happens that you move the chair with casters that rub instead of ride, and that's precisely what I want to avoid the floor! So I drilled a hole on top of each wheel, to bring out the locking spring .. Thus, the wheels are clear at all times.
