This knife sharpener from KitchenIQ (formerly Edgeware) features ceramic triangular stones that will not remove as much metal as carbide and is ideal to maintain the edge of both your straight and serrated knives. The sharpener has 2 stages, one for fine and one for extra fine. The pull-through knife sharpener also allows to hone the inside of the large serration on bread knives and has a sliding plastic guard that ensures the proper slots are being used for every type of knife.