Spyderco Ultra Fine Triangle Stone will put an shaving sharp edge on your knife. It is what you have been missing to get your knife as sharp as it can get . The triangle shape allows it to work for plain or serrated edge knives ,it also features a groove to sharpen your fish hooks with. High Alumina Ceramic construction Ultra Fine grit. This rod can be used by its self but works best as part of the Sharpmaker System. This is one rod, not a pair.