Packing: 4inch 30 Grit Metal Diamond Polishing Pads 1Pcs Diameter 101mm, total height 9mm, inner hole 19mm, dry polishing, can not be used Wet Sanding the material. Concrete, granite, marble, glass, stone, tile, stone, glass, ceramics, hard plastic, fiberglass, etc. The back is made of high-quality cotton, which is easy to be hooked by Velcro Sharp, high grinding efficiency, wear resistance, long service life Sharp, high grinding efficiency, wear resistance, long service life