When that time comes that you need to touch up the sharp edge of your Wusthof knife the Diamond steel is a good option. The Wusthof 9-inch Narrow Diamond Steel can align your knife edge and unlike traditional steels, the Diamond Steel also contains fine abrasives that will sharpen your knife as well as re-aligning the blade. Used like a traditional honing steel the diamond steel is very fine and and can bring up a very fine edge.