This professional Sharpener puts a razor-sharp edge on both straight and serrated blades, without destroying the temper. This well-engineered system uses a three-stage process in which blades are sharpened and honed on 100 percent diamond abrasive belts, then stropped to give the blade a fine, smooth edge. The three-stage heavy duty patented sharpening process allows you to select the type of ultra-sharp edge preferred for the knife's intended use. The sharpener automatically aligns blades to the correct angle. Great for sharpening kitchen knives, sporting knives of pocket knives, as well as serrated bread knives. Specially designed guides align blades to the precise angle.