Installed in a polymer80 - Magpul Industries GL Enhanced Magazine Well

So this review may not be "fair" since it was installed in a polymer80 PF940C and not a Glock 19. 1st, you cannot screw the screw in all the way or it will pop out so you have to back the screw out so it catches on the frame. I'll probably try to find some thicker screw heads for attachement. Once attached, the magazine would not seat properly. I had to take some time and sand/file out the interior of the magwell extension until it was flush all the way around. Once that was done, it functions fine. My Magpul mags seat easier than my Glock mags with this extension. So bottom line, it works but requires a bit of extra elbow grease to function.