Literally doesn't fit - Lancer Systems L5AWM AR-15 Basepad 6 Round Magazine Extension

Had a single person tried to fit these to a magazine, they'd find that it doesn't fit. Not fully, at least. You can install it, sure. But don't expect to get 6 extra rounds to fit. The base of the magazine spring assembly sits at an angle inside the extension, due to an internal shelf. Because it's at this angle, the base part of the spring sits too high, so you can only get an extra 3, maybe 4 rounds if you really try. Get the third party ones, because apparently, these guys are too incompetent to actually test their own product to see if there are any geometric collisions that prevent full operation. The third party ones I initially bought fit great and run awesome. But do not buy these things. I'll continue to try to get them to work, but I already broke a magazine by bashing it against the ground, as that was the only way to remove and retry to fit it again. I'm beyond frustrated at spending over $100 on these things that simply don't fit. You'd think that the guys who make the magazines would be able to figure this out. Avoid buying these, go with the third party folks