Shapton Glass Ceramic Water Stones are the finest manmade ceramic water stones….period! This claim is based largely on two properties - the speed at which the Shapton stones cut and the edge they create. Shapton stones are designed to be harder, faster cutting, and denser than any other ceramic water stone on the market. Because they remove material quickly, the time required to hold a tool angle on the stone is reduced, making free hand sharpening much easier. Equally important to cutting speed is the consistency of the finished edge. The sharpest cutting edge is created by the finite intersection of two highly polished, flat surfaces. The finishing grits (16000 and 30000) of the Shapton stone system leave a polished surface free of the scratches creating a mirror finished, razor sharp edge. Each stone is comprised of a 5mm thick glass backing plate fused to a 5mm thick stone and measures 2-3/4 W x 8-1/4L. We recommend purchasing, and using, the Shapton stone holder. As it provides a secure platform and protects your stone when in use