Features: Made of diamond and sponge material, high hardness, wear resistance and with fine durability. Groove design on the side, easy to grip and easy to use. The finer the grit is, the finer grinding effect gets. The coraser the grit is, the finer polishing effect gets. Mulit-purpose, it can be used of tile, glass, wood, and metal(according to your selection). 4 different colors with 4 different grits, 60# red(slate floor tile), 120# orange(ceramic tile), 200# green(glass), 400# purple(fine grinding), you can choose according to your demands. Wide applications, suitable for trimming edges, removing burr and grinding edges use.