The 4” Coarse Diamond Sharpening Stone also comes with a Micro-Tool Sharpening Pad™ for sharpening the tips of your knife blade and small tools, a straight-line sharpening groove for fishhooks and pointed objects, and a stone cover that doubles as a base when not covering the stone.4" Diamond Sharpening Stone - Coarse It is excellent for sharpening even the hardest steel blades and works best on small to medium hunting knives, tactical knives, and everyday pocket knives.