Ok, Heckler & Koch makes the mp5 and the mp5 k. They look similar, and they both work on a roller detent blowback fireing mechanism. The mp5 comes in six different configurations, with things like, silencer, solid stock, foldable stock, the popular "navy" trigger grouping
, and a teloscoping stock(wich looks nothing like the commando stock). The mp5 k (the one with the foregrip, like the A-5) has either a folding stock or a solid stock, no commando stock. I swear I'm not a right wing militant.