This stone sharpens fast & efficiently, outlasting & out-sharpening metal files. The elliptical shape makes it conformable to all flat & curved cutting edges. Use on a broad range of tools including pruners, clippers, trimmers, sod cutters, hoes, trowels, pitch forks, lawnmower, edger or groomer blades, hedge, lopping, or grass shears, transplanters, shovels, spades & cutters. The benchstone is made of premium coarse grit silicon carbide abrasive. Lawn and Garden Sharpening Stone.  Norton Crystolon.

    To obtain best results, lubricate your stone with genuine Norton Sharpening Stone Oil. Oil acts as an effective lubricant during sharpening to float away metal & abrasive particles that would otherwise clog up the stone. When metal particles clog the stone pores, it's called glazing & can ruin the stone.

From the Manufacturer:

   Norton Sharpening Stones are made of the highest quality materials & are unequaled for long sharpening life, maintenance of shape & smooth cut.