Kyocera Advanced Ceramics Kyocera's multi-use Sonic Wave sharpener has an advanced ceramic sharpening wheel, a material close in hardness to diamond. The material strength of this sharpener will provide a razor-like edge on steel knives, scissors, blender blades, carving tools, fishing hooks, pruning, hedge, grass, and lopping shears. Requires two AA alkaline batteries, not included. To sharpen steel knives, attach the guide cover which is included. Place the Sonic Wave Sharpener on a solid surface, such as a table or counter top and hold it steady. Turn it on and pull the knife through the guide. If the knife is double edged, it must be sharpened on both sides. Turn on the Sonic Wave Sharpener and touch the advanced ceramic grindstone to the edge of the surface to be sharpened.