I purchased this knife sharpener to use on my set of Wuesthoff knifes. My knives were beyond dull and in really poor shape. I bought this hoping the three stages would be capable of sharpening even my dullest knife. I have to say it worked wonderfully! I followed the instructions exactly and it was easy to sharpen all my knives. I love that it was easy to use, sharpened my knives well, and will also be cheaper than taking my knives to be professionally sharpened!