I have the grinder still ordered because I was simply interested in whether it could function at all or if you order a lawnmower blade gets hot.
First I got the grinder in my Kress Cordless screwdriver tested on a built-in meter. Since the force and the speed of the cordless screwdriver enough not look.
But I was able to find that, as expected, it comes with the slider just to the middle part of the knife. Quite outside is not possible, since one abuts yes. So is the promised grind impossible when installed.
Then I stretched the grinder in a drill and the blade in a vise. After 10 minutes, I realized that the plastic stopper adopted slowly and you can see the knife sharpening no. It was still dull as before. The grinder will perform as well as any material.
Conclusion: This thing does not work and is a 10-minute scrap.