My kids were very good at abusing DVDs, so I used this item extensively. Minor scratches and smudges were neutralized, but deeper scratches could not be fixed well enough to render those sections playable. The device gives several options of repair: 1. Cleaning; 2. Repair; and, 3. Deep repair, which claims to remove the top layer of the disc, to level out scratches. I found that if the first 2 methods didn't work, neither did the 3rd. Even repeated treatments didn't work for deeper scratches (I'm using "deeper" as a synonym for "not minor"). Bottom line: this is useful for some problems, but will not work miracles.