DMT FFF Diafold Diamond Flat Folding File Fine Portable, lightweight with convenient fold & go handles which enclose and protect the diamond file when not in use Fine diamond for a razor sharp edge Sharpens knives faster than conventional stones with DMT's monocrystalline diamond surface No oil is needed-sharpen dry or with water Durable construction will provide years of consistent performance and reliable service Fine diamond for a razor sharp edge Sharpens knives faster than conventional stones with DMT's monocrystalline diamond surface No oil is needed-sharpen dry or with water Durable construction will provide years of consistent performance and reliable service