My post above was a little confusing with respect to the edge comment. I wrote it poorly but what I meant to say is since it is a long throw DA (orbital), if you get the edge of the pad too close to a raised portion of the cars body work it will make contact with it as the pad orbits back and forth. The foam pad I used was larger than the backing pad so I could get close to raised body work since there was excess soft foam pad. Don't get overly close or the hard backing pad can make contact with bodywork. Again, way easy to use and I am really happy with it.