Diamond grinding sets are used for very hard types of steel or to more quickly recover a sharp edge on very dull weapons. The fastest and easiest way to sharpen your knives. This knife sharpener from Lansky is safe and easy to use and ensures you a sharp knife every time. This grinding set contains 3 different stones, a coarse diamond grindstone, a medium diamond grindstone and a fine diamond grindstone. We recommend purchasing a table holder, as it significantly facilitates the sanding work.