This FastEdge 2 stage Manual Knife Sharpener & Hone has Tungsten Carbide Inserts for sharpening and ceramic inserts for honing your straight edged blades. This sharpener will make all your straight edge steel knives razor sharp with just a few passes. Days of dull knives are gone with the Ergo Chef Fast Edge knife sharpener. Cuts both sides of your blades edge for sharp results by following easy instructions on box. This Sharpener takes the guess work out of angles and makes it simple for anyone to sharpen there dull knives. Environmentally friendly by design to re-use the handle & simply change out the replacement cartridge when needed (Usually 1-2 years depending on use).