UMAREX 12rd Co2 Magazine for Beretta M84 FS Series Airsoft Pistols - Black

"Works just as well as the included mag. No leaks, gas efficiency is pretty alright, my only sort-of complaint is the capacity (12 rounds) but I'm not very pressed, given that it's a smaller pistol. Also to note, although I've mixed the two, one of them drops freely while the other needs encouragement to come out by itself. Not sure which was the extra mag, but just keep in mind that they might behave differently when releasing the mags.