Smith's 8" Diamond Tri-Hone Sharpening System is excellent for sharpening pocket knives, hunting and fishing knives, kitchen knives, and tools of all sizes. Includes two interrupted surface diamond stones and a medium Arkansas stone. The coarse (325 grit) and fine (750 grit) diamond stones feature a unique, overlapping hole design that speeds sharpening by collecting and holding the metal filings which build up during the sharpening process, thus allowing the stone's surface to remain clean and clear. The Natural Arkansas stone (approx. 1,000 to 1,200 grit) is best used for finishing your edge and it removes moderate amounts of metal as it polishes the cutting edge.