The DMT 6 in Dia-Sharp is a double-sided continuous diamond bench stone, 6 x 2 in, in coarse/extra-coarse, fine/coarse, extra-fine/fine or fine/extra-coarse.
Both faces have a continuous diamond surface, and the grit is marked on each side. It sharpens knives, blades and small tools, and DMT says it will also flatten conventional and water stones. Sharpen dry or with water; no oil is needed.
DMT, short for Diamond Machining Technology, was founded in 1976 by aerospace engineers. It started out making grinding wheels, and its first hand sharpener was made from the center punched out of a diamond grinding wheel. A buyer at L.L. Bean tested an early sample and worked with DMT's engineers to refine it. Acme United bought DMT in 2016, and DMT is based in Marlborough, Massachusetts.