I've tried some knife sharpener. With a simple grindstone I got along very well. By means of a Youtube Filmchens I've acquired the basics of sharpening knives and then practiced. My knives are habitually very sharp. If only the many time would not have been that one spends in regular loops. - I want to be brief: this device controls the correct grinding angle and thus one of the main "secrets" of grinding of principle. You press the knife to a support surface, preferring swiftly to very fine abrasive band over which the right angle is running just on the edge. Then you change to the other side and repeated the whole thing. Again, Youtube provides a few movies for those who want to know for sure. After the blades are sharp! Even sharper than I was previously accustomed. Once a grinding noise, I took the same nor the scissors in the house before - and then the knives and scissors of the family. In other words, this device does what it should - and really good, quick and easy.