The 15XV 3-stage professional knife sharpener is the ideal solution for 15-degree class knives. Using 100 percent diamonds, the hardest natural substance on earth, our patented abrasives sharpen edges faster and easier. This straight-edge and serrated knife sharpener improves cutting performance by creating 3 distinct facets set at different angles to form a longer lasting, ultra-sharp edge. The first stage sharpens straight-edge knives using medium abrasives, while the second stage uses finer abrasives to hone the knife edge. In the final stage, patented stropping disks create an unparalleled polished finish. Precision angle guides ensure accurate sharpening throughout the entire blade length and eliminate any guesswork. In addition, this sharpener can easily convert a traditional 20-degree knife edge to more precise 15-degree edge. This unit is designed to work with both straight-edge and serrated knives.