There are plenty of Youtube videos showing salesmen at outdoor oriented shows hawking various freehand carbide sharpeners. They are all able to turn a dull blade into shaving sharp in just a couple of minutes. The carbee sharp is also a free-hand (as opposed to "V Groove") carbide sharpener. It's different from the others in that if you turn it over there is a polishing set of carbide blades.
Do not expect to pick up any carbide sharpener and turn a butternknife to razor sharp in two minutes. You need to understand how to use the tool and practice, practice, practice. But before you know it, you'll be ready to sharpen knives at Carnegie Hall.
The best set of instructions for the Carbee-Sharp are at https://www.garrettwade.com/images/art/carbeedoc.pd
Follow the directions and it will work like magic.
This little tool also sharpens scissors, axes, pruners, fish hooks. It gives great sparks when used as a ferro rod striker, and can put a sharp spine on your knife for that purpose.
Because it takes some learning, I'm only giving 4 Stars. When you learn how to use it, you'll give it 5.