Cutting with a dull knife can be dangerous. It is important to maintain your steel knives in between uses. The dual-sided surface of Kyocera's sharpening rods provide for sharpening and honing a blade. The ultra-efficient sharpening rod is made out of advanced ceramic, a material close in hardness to diamond. The durability of this rod will provide excellent results when re-sharpening or honing the cutting edge of your metal based knives, scissors and cutting tools. When your metal based knife or cutting tool is extremely dull, first use the ribbed side of the ceramic rod to sharpen the blade by creating a finely ribbed texture on the primary cutting edge. Follow by using the smooth surface to hone or finish the edge.