Extra Fine # 1200 size: 8˝ x 3˝ x 3/8˝. DMT's new DiaSharp diamond stones feature a continuous diamond surface that quickly puts a razor edge on knives and tools. DiaSharpT is manufactured exclusively with Monocrystalline diamond crystal super-abrasive known for long life. The monocrystalline diamond particles are deposited onto a metal plate surface that will always remain flat and will never chip or crack. These stones can be used to sharpen any steel, carbide, glass, ceramic or even titanium. They are perfect for woodworkers, gardeners, hunters, fishermen, chefs, campers and other craftsmen. The 6˝ size gives you 12 square inches of continuous diamond surface. The 4˝ size is perfect for hard to reach spots and hand held applications in the garden or in the field. The 8˝ and 11½˝ stones are the perfect sizes for serious woodworkers.