it's basically a system designed to look like a version 2 gearbox. i heard the mags are proprietary because of the design. it's a unique gas system. GHK makes a drop in kit but i'm pretty sure G&G made this one. it only makes sense. i would wait for it to come out and read some reviews. i would also wait and see if G&G will be selling extra mags because it would blow to have only 1 mag. besides the gbbr aspect, it is a combat machine AEG on the outside. even the pictures on GI show the bodies of the gun saying "AEG" so you could use the gun as a prank too. all in all, wait a while after it comes out before you decide to get it but if you are one who likes to take risks then go for it. i might get one as long as there are extra mags. if you do get one let me know how it is.