Simple, effective enough.

Simple: easy to use to sharpen a blade well, it will be hard to find.
I passed the gun I knew that only use for this sharpener that everyone uses in the house = I'm not the only one to sharpen the blades! The knives are now maintained even when I am not available.
The product does not work miracles on a very worn blade: one must pass a dozen times in the blade sharpener to achieve a good result.
Small disuse: the sharpener suitable for straight blades: for curves and used blades, it would change the shape of the head to refine a little of everything, otherwise rubbed plastic.