Wusthof Sharpening Whetstone Knife Sharpener.

This whetstone from Wusthof has a coarse grain side and one with a finer grain. The grey side of the stone (with the coarse grain) is suitable for removing small flaws and dents and to prepare the edge for honing. The green side (with the finer grain(240 / 800)) is used to hone the edge to the desired sharpness. Using gentle pressure, simply pull the edge of the blade in a 20-degree angle across the stone from the heel of the blade to its tip. Repeat this same procedure on the other side of the edge. Before each use, immerse the stone in water for 5 - 10 minutes. Always place the stone on a flat, slip-resistant surface, and use the entire surface of the stone when sharpening. This will ensure even wear of the stone over time.