Diamond Bench Stone: Accomplish all of your sharpening jobs with the diamond Bench Stone, comes with both #300 and #600 grit. These stones are the ultimate in sharpening technology. Multiple layers of micron-sized diamonds bonded in nickel to a flat metal surface. The Coarse #300 grit aggressively removes metal to restore edges on dull knives and tools. The Fine #600 grit finishes knives and tools with a razor-sharp edge.