I have 3 now… - FAB Defense MG-9 Foregrip And Magazine Carrier For Double Stack 9mm

So these things are awesome. I have 3. One for the S&W M&P FPC 9mm, one for Beretta Cx4 Storm 9mm, and Christensen Arms CA9 9mm (Glock mags). I haven’t “torture tested” one, but I did test its retention for each mag that I attached to its designated weapon prior to installing it on its weapon. It is very sturdy; it doesn’t wobble at all when properly installed. Retention of respective magazines seems great when customized to the magazine type in question. You can easily remove the mag by using your thumb on a spot that seems made for using it (not entirely sure it was made for it, but it works). It’s a great item that may or may not skirt some regulations about use with pistols since it’s a mag holder. Would definitely recommend with any double stack 9mm magazine for a carbine in 9mm.