𝐉𝐔𝐍𝐋𝐈𝐗𝐍 10 Pcs 25 mm Bullet Shape Rotary Grinding Stone - 1/4 Inch Hex Shank Abrasive Stone Mounted Grinding Point for Drill

First the good. These are good grinding bits, and there's a variety of shapes, so you're bound to find what you're looking for. They grind most materials well, but I find them to be most useful sharpening garden tools (lawn mower blade or metal wedges), removing burrs off of cut metal, or a general purpose grinding bit when you can't bring something to the bench grinder. My issue is this is advertised for die grinders, rotary tools and drills. It's really only for drills, because to my knowledge, all rotary tools have a 1/8" chuck and this is 1/4" and die grinders take round shanks, and this is hex. So you can really only use this on drills. I assume the vast majority of you know this, but thought I'd point this out to the random person who might not. It's a good set for the drill though.

For the money I'd say this was a good purchase.

Doesnt hold properly to my tools, not locking .

Whenever I need a grinding bit, I always seem to have one that's too small or the wrong shape.This kit solves that problem, I should have the right size and shape grinding bit for every need for years now. They seem to be made well enough for light use, at a surprisingly inexpensive price.