Shapton Glass Stones are known for their exceptional quality, durability and ease of use. Unlike other waterstones, Shapton Glass Stones do not need to be soaked in water before use - simply wet the surface and begin honing your blade.Shapton sharpening stones are made with finely graded ceramic cutting media that requires less flattening and lasts 4-5 times longer than most water stones. The abrasives in these glass stones are also extremely uniform, meaning the abrasive encountered with the first pass of a blade will be the same as the 5000th pass. Each stone is comprised of a 5mm tempered glass backing plate fused to a 5mm thick stone.The #4000 grit stone has a particle size of 3.68 microns and this High Carbon version is particularly effective at polishing high carbon steel edges, therefore it is ideal for sharpening high carbon steel straight razors and other high carbon steel tools. Used in combination with the High Carbon (HC) #8000 grit stone, you'll have an edge that you can shave with. We recommend using the Shapton Stone Holder to hold the stone in place when in use.