A revolutionary advancement in knife sharpening! The astonishingly sharp 15-20 Degree edge for ultimate sharpness and effortless cutting. 2-Stages: Combines the strength and durability of the double-bevel edge with the flawless, ultra-sharp XV edge technology. This versatility sharpener sharpens: chef's knives, Santoku knives, serrated knives, cleavers and sports knives. Sharpener converts traditional 20 Degree factory edges of European and American household knives into the high performance 15 Degree edge.