This Trend standard professional Double-sided bench stone is for up to 3 '' plane irons and chisels. The unequalled clearance channels faster, cleaner cuts. to a tolerance of + / - 0.0005 inch flatness and comes full-blown with pouch, cleaning block and non slip mat. The diamond-shaped surface snagging when sharpening minute or peaked tooling. with no pressure. chisels and plane blades and achieve a shaving edge in seconds. The precision flatness you sharpen spindle knives in house.