Combining electric and manual stages, this hybrid sharpener is the ideal solution for improved cutting performance on 20-degree class knives. Using 100 percent diamonds, the hardest natural substance on earth, our patented abrasives sharpen faster and easier to create an ultra-sharp, longer-lasting edge. The final stage delivers a polished finish. Precision angle control ensures accurate sharpening throughout the entire blade length. This unit is designed to work with both straight-edge and serrated knives. Why you need a knife sharpener – over time, a knife’s edge dulls under the stress of cutting. The overall performance can be significantly improved if sharpened and maintained correctly. How do knife sharpeners work – good sharpening systems shape the knife edge with a coarse abrasive and polish with a finer abrasive. Covered by the choice three-year limited warranty.