Chef'sChoice Professional Electric Knife Sharpeners Sharp-N-Hone With 100-Percent Diamond Abrasives And Precision Angle Guides For 20-Degree Straight-Edge and Serrated Knives, 2-Stage, Gray

I've tried about ten different ones, this is the only one that matches the description completely.

works great

I have never seen a knife sharpener which actually made my knives worse. Extremely disappointed.

Being in a high volume non-profit kitchen, I wanted a NSF rated sharpener. There are a variety of people using this - professional and volunteer alike. I needed something simple and well built. This is just that machine.The knives come out sharp easily, if (big IF) you read the easy instructions.The people who say it ruined their knives must not have read the instructions. I honestly don't see how they could have messed up any other way.I have a Norton Tri-stone manual sharpener, a Work Sharp band sharpening (excellent also) and this. This is by far the easiest and best bang for the buck.This is simple, straight forward, NSF rated, and effective.