The Wüsthof 10” Diamond Sharpening Steel is fantastic for maintaining your Wüsthof knife edges. The steel is coated with diamond dust to easily align the small teeth that are on the edge of every knife. As a knife is used, the teeth become flat, reducing the blade's sharpness. The fine grit on this steel will give your knife a more polished and sharp edge. At 10 inches, this diamond steel is recommended for knives 10 inches and smaller.