Have long sought a good grinding media for quality knives. I wanted it simple and do not work with a grindstone and oil. Among the simple systems this Minosharp system came in the way best reviews. All found it top and have long written reviews - which had convinced me and stopped me from further reflection, unfortunately! The system works because the knife is tilted by the lead in the grinding roll quasi. No matter from which side you pull the knife through the guide / push, the canting always remains the same, which means that the diameter at the top are cut only from the left and back towards the handle just right at just over 1 cm length. Only the area in between can be sanded from both sides. In other words, you hereby forms an S-shaped cutter (ground only left at the top, in the middle of both sides and the rear is only right ground). Who wants the so-slightly hurt his knives? To this thing one only comes around when one folds away the clear plastic cover of the guide and freehand knife tried on the other side tilting. But this is not easy, not professional and certainly not thought so. That such a device is recommended by a knife sharpener association, I can not understand. Whoever with the idea to play zuzulegen this equipment, should first try to understand my description here (am not sure whether I have made myself clear) - no matter from which side it runs through the meter or pushes, the tip only left sanded and the region towards the handle just right! Or is an "S" in the blade for you okay? I'll probably not drumrum a grindstone!