Guaranteed not to hollow or groove, DMT’s precisely engineered Dia-Sharp Bench Stone with continuous diamond surface assures consistent, even sharpening every time. The 8″ length is great for both long and short knives providing cutting edge performance for a quick, keen edge on small contact areas and pointed tools. Perfect for flattening plane soles, irons and chisel backs—even conventional and water stones. Includes non-skid rubber feet. Diamond grit clearly marked on side of stone. Extra-Coarse grit. Extra-Coarse diamond (60 micron / 220) when significant removal of material is needed for damaged edges. Sharpening surface accommodates range of edges— from large knives to small pointed tools. 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.WARNING: use of this product can expose you to chemicals including nickel which is known to the State of California to cause cancer. For more information go to www.p65warnings.ca.gov.