The 15” Magnetic Resin Bonded Smoothing Disc puts a smooth velvety finish on either ground or slightly rough ceramic surfaces with this disc. It is a pliable, durable magnetic backed resin bonded fiber that is saturated with fine diamond particles. The smoothing disc is used to sand and polish ceramic material rather than to cut and remove it. This disc attaches magnetically to the more rigid electroplated grinding disc as well as directly to the steel plate. It can also put a fine hone on metal trimming tools and ribs. Use with water.