SHARPAL 121N Dual-Grit Diamond Sharpener is excellent for sharpening even the hardest steel blades and works best on hunting knives, tactical knives, everyday pocket knives and tools edge. Industrial monocrystalline diamond is electroplated in nickel onto a stainless steel base. With industrial precision flat, hard wearing surface and durable design, it guarantees consistent, even sharpening for years of dependable use. It is double-sided with both coarse and extra fine diamond surfaces. Use the coarse side 325 grit (45 micron) to quickly and easily restore a dull or damaged edge. Use the extra fine side 1200 grit (9 micron) to hone. Sharpen dry. No messy oil needed.