DMT W8CNB 8-inch Bench Stone Coarse with Non-Skid Mat Superior diamond sharpening stones Legendary quality Made in the USA Fine diamond for a razor sharp edge Coarse diamond to transform a dull edge Sharpens knives faster than conventional stones with DMT's monocrystalline diamond surface No oil is needed-sharpen dry or with water Durable construction will provide years of consistent performance and reliable service