Quickly hone a razor-like edge with the uninterrupted diamond sharpening surface of DMTs Double Sided Dia-Sharp stones. These continuous diamond surface stones provide cutting edge performance and are recognized for their superior quality. Sharpening with diamonds is fast and easy. No oil is needed. You can sharpen dry or with water. Coarse grit quickly restores edge on a neglected tool or blade; Extra-Coarse grit is perfect when significant removal of material is needed for damaged tools; Fine grit puts a keen edge on a regularly maintained edge; Extra Fine polishes and refines a razor edge after sharpening the tool or blade on a coarser grit. Also great for water stone flattening.