Jewelers, gunSmith's Sharpener, wood carvers and dental professionals all at some time have a need for small sharpening stones. Spyderco's 400F Ceramic Files include the following shapes: Round, square, triangular, and slip. All four stones are fine-grit ready to debur hardened tools, molds, even carbide. Sold as a set of four, packaged in a snap-front suede pouch. Clean with a plastic souring pad and powdered abrasive cleanser. They are autoclave safe.