I'll save you from the rule...
Got one. Works pretty good. Not really small enough to fit like a knife, but looks like one from the outside. Great if you are carrying a slim low capacity single stack and want more ammo discreetly. I will say it can be tough to draw from. The pocket clip doesn't always stay tight on your pocket and the holder tries to come out with it, but it has that little "snag" feature that will grab your pants if you pull it up the right way and strip the carrier off the mag. Carrier usually falls on the ground at that point, but if you are in a situation where you are pulling your second mag, you probably don't care. A small bur on the pocket clip would help it cling, but would tear up your pants a little.