The DMT Unbreakable Ceramic and Diamond Ceramic knife sharpeners are created by the CeraFuse process that transforms an aluminum surface to a dense, hard aluminum oxide. The end result of this process is a knife sharpener with the same properties as ceramic, without the worry of breakage. Choose from Diafold Ceramic with tapered rod for sharpening serrated edges. Ceramic Steel with classic butcher's steel design. Diamond Ceramic 6 in 1 Sharpening Tool triangular shaped rod with 7 micron ceramic, 600 mesh fine and 325 mesh coarse grit diamond flat surfaces. Use the Coarse (325 mesh) diamond flat surface to restore the edge on a neglected blade. Use the Fine (600 mesh) diamond flat surface for the next step to a razor edge. Use the 7 micron Ceramic flat surface for a polished finish edge. The ceramic corners of this triangle sharpener also have 3 different sized radii for sharpening different width serrated edges.