I'm going to hit the ground running on this one. Benchmade, the maker of some amazing knives. Apparently they couldn't make a knife sharpener if one bit them in the rear and asked to be sold. All you hunters out there I'm sure most of you can tell me the angle you believe is best on your hunting knifes edge. I would bet money that the majority is closer to 20 degrees than it is 25. The only tool I have with a 30 degree hard edge is my machete. You can't cut much of anything with a 30 degree edge unless you are hacking. My multi use knives are at a good 25 my knives for food and meat at a 20 or so. I bought one of these for my girlfriend since I wasn't around all the time to keep her knives sharp. I didn't give it to her all this would do is mess up all the work I put into making them sharp. Aside from that, if you are using a machete, a broad sword, or any blade about as long as your forearm....this is the sharpener for you. Worked good on my machete, not as sharp as when I do it by hand but a lot better than it was in a lot less time.