speci: 150*10*12*31.75mm cup type,resin bond, very fast cutting very long life diamond grinding wheel metal bonddesigned for grinding jewelry, gemstone, porcelain, glass,and other non-metal materials.flat type,metal bond, very fast cuttingvery long lifediamond component: 100% we also can make other shape,and other specifications.we also can make other specification, from 50mm to 200mm