There are a half dozen 45 ACP pistols on the market that take double stacked mags like you picture. They could be para ordinance or an XP or several others that I can think of. As for the 9mm mag there are several dozen pistols that take mags like you picture each differing a bit in length, hight and positions of the locking knotch. I own several myself and each looks exactly like every other one except for minor differences. I personally have marked and segregated my extra mags so that I do not get them mixed up which happened one time to me and it was most embarising when I tried to insert a mag from my Taurus PT99 into my CZ 75B. It went in but would not lock in. I eventually placed all my mags on a table along with all my pistols and tried them. I then color coded them to the gun and store them in separate boxes that are labeled for the gun in question. The only ones that I did not have an identification problem with is the Ruger P series 9mm guns as the mag catch notch for all of them is directly in the front of the mag and they are interchangable between models.