4 steps: professional knife sharpener, coarse grinding, fine grinding and polishing. The scissor slot is for sharpening scissors, tungsten steel for sharpening old knife edge, emery for sharpening dull knife and sharpening blade, ceramic stone for precision sharpening. Always grind in the same direction to polish, sharpen and shine edges. Non-slip design: The non-slip rubber base ensures maximum stability and safety, preventing the sharpener from slipping. Can be used safely on a wooden, stone or glass desk. Easy to use: place the knife in the slot and pull towards you 5 10 times. Do not push or pull multiple times during the sharpening process. Always sharpen in the same direction. After sharpening, clean with a damp cloth. Ergonomic design: the ergonomic handle offers a comfortable and stable grip. Safer and labor-saving, comfortable grip, flexible operation and light weight. The materials used in knife sharpeners are tungsten carbon steel, ceramic stone and diamond rods. Usage: The knife sharpeners are suitable for steel scissors, fruit knives, chefs knives and short boning knives, etc. (not suitable for ceramic, serrated, ondul knives).