You rub the scratched disc in both a clockwise and counter clockwise direction on the surface of the Disc Genie which smooths out the scratches and allows the laser to continue reading the disc. The way it works is it is abrasive enough without being to abrasive to smooth out the scratches on the disc. It doesnt erase the scratches visibly but it smooths them out so that the disc can be read again. I have one that I've used twice and it has worked both times.