Grit: #50,#100,#200,#400 Metal Bond Diamond Grinding Disc is specially used for Rough Grinding..... Metal Bond Diamond Grinding Disc is specially used for Rough Grinding.Dia: 4",6",8",10"Grit: #50,#100,#200,#400Any question, pls feel free to contact me.Henry Chan (sale08) Metal Bond Diamond Grinding Disc