sandpaper. No sand, no paper. To discuss! No, but seriously, it was a great purchase. 3 pieces of each gradient from 120 to 3000 for how much? You can easily spend three or four times as much and not on as many hands. Although this is a universal kit. It takes care of almost every project you need; However, depending on what project it is, it may only care about one project. Whatever the case, this is a great buy. One note: store your sheets in a ziplock bag or something else that will reduce moisture. Otherwise, these suckers will curl more than Curly Sue's hair.