The Edgelogix 4 Stage Sharpener has three sharpening stages for straight-edge knives and one for serrated knives and scissors.  The ergonomic design with a non-slip rubber base and handle is safe and easy to use. Simply place your knife in the correct slot depending on the dullness of your knife—coarse (carbide) to restore an edge, medium (diamond) to refine the edge, and fine (ceramic) to hone an edge and pull the blade through. The fourth stage is to be used for serrated knives or scissors only.