Ansen Tools Grit Sharp AS-409 6-Inch Double-Sided Extra Wide Diamond Whetstone Sharpener Coarse/Fine in Compact Case with Non-Skid Rubber Base Double-sided (Coarse 360 grit - Fine 600 grit) each with monocrystalline advanced technology Coarse surface (360 grit) quickly restores a dull edge and the fine diamond surface (600 grit) will bring back a razor sharp edge Sharpens the toughest materials like tool steel, carbide and ceramics Ideal for machine tools, cutlery knives, woodworking tools The sharpener sits in a compact case with a non-skid rubber base