Made of the same ceramic material of the famous Triangular rods, this is a medium ceramic bench stone. While many manufacturers use the terms medium to mean a rather coarse level of grit, the Spyderco Medium is more comparable to other stones described as fine or even a little finer. The ceramic sharpening surface is very hard and durable. These ceramic stones are to be used dry (no oil or water). Cleaning is easy, just use a plastic abrasive pad and powdered abrasive cleanser. Stone measures 8" x 2".