This keeps my knives like new out of the box sharpness. But you have to be careful when you use pull thru sharpeners. You should not use pressure when sharpening the knife. Just let the knife glide on the sharpening blades. When you apply pressure, you might damage the blade. I have pull thru sharpeners, Japanese Waterstones, Wusthof Steel Sharpening Rods, Smith's Tri-hone and Spyderco Sharpmaker. I initially started with the Accusharp and Smith's Jiffy Pro Knife sharpeners. I got really great results from both of them, but I got swayed by "Experts" that said that it is taking away too much steel every time I use them, and it also damages the edge. So, based on their advice, I bought a Spyderco Sharpmaker. It was great and very sharp, but I could never replicate the edge exactly every time. So, I turned to Japanese Waterstones based on suggestions from others. I have to say that they were able to produce a crazy sharp edge, but it took FOREVER to sharpen a Kershaw Blur. Through all of this, I noticed that my knife was getting smaller and smaller. So I did not get the logic of not using the Pull thru sharpeners in the first place. I have been using Pull thru sharpeners for many years and I never noticed my knives getting smaller! Now purists might say that it is because I lack experience with using Stones or Rods, and that may be the case, but I do not want to spend any length of time perfecting how to sharpen a knife, as I have more important things to do. The Smith's Sharpener gets the job done in less than 20 seconds. But what I do agree on was that pull thru sharpeners changed the edge angle. If your pull thru sharpener has an angle of 20 degrees, it will impart that to your knife. Spydercos I have been told are approximately 30 degrees in total, about 15 degrees per side. So with this I used the 14 degrees setting and sharpened my Spyderco Tenacious(I am not going to experiment with my more expensive Spydercos). I have been cutting cardboard boxes everyday(Amazon packaging boxes) to see how durable the edge is. It has been a week and the knife still cuts well. Obviously not as sharp as when I initially sharpened it, but it can still slice the boxes with only a slight roughness. After a week, I ran it thru the FINE Ceramic Sharpener and the edge is back. Always try to sharpen your knife on the FINE Ceramic first, and if you find that it is not sharp enough, only then should you use the Tungsten Carbide blades. You DO NOT need to use pressure when using this. Just lightly swipe your knife and keep checking every couple of swipes if it is already sharp. When you use it gently, this will not take of anymore steel is needed. The FINE ceramic will be take off very little steel. So in summary, this preserves you knife's factory edge and produces a very sharp edge for most tasks. I highly recommend it. I purchased mine from the KENCO(Amazon seller) because I find that they have excellent customer service. ******UPDATE***** I find that the best use for this is to reset the edge angle. Once you have run thru the COARSE and FINE sharpeners, you can finish off with an EZE-LAP Super Fine Diamond Rod ($20) to give it a really smooth and sharp edge. I actually noticed a difference in the way my knife slices thru paper, before and after using the EZE-LAP Super Fine Diamond Rod. You can use the EZE-LAP much more frequently as a Steeling rod and super fine sharpener since it removes the least amount of Steel from the blade. Then just use the Smith's Adjustable to sharpen a dull blade or for a quick sharpening.