HSGI is a company that most of us associate with good quality equipment and one specific model of magazine pouches: TACO. It was HSGI who invented and patented this type of simple yet genius device, allowing for transfer of many types of magazines.
The above-mentioned pouches, specifically the X2R TACO model, will be delivered in the number of 150,000 units to the US Marines.
The Double Decker design allows the user to carry 2 magazines in one pouch while taking only about 3 inches of space on the mounting panel.
The X2R design uses injection molded polymer brackets, Cordura at the front and back, a shock cord and a thin HDPE (high density polyethylene) sheet to separate and secure almost any combination of magazines. The USGI, HK, PMAG, ARC, FAL, AK 30/40, LR20 and M14 magazines can be safely stored and taken out easily and quietly.
Sources: soldiersystems.net, twitter.com/highspeedgear,highspeedgear.com