BLACKHAWK CQC Magazine Case, Single, Double Row, Matte, Black 410600PBK Their Single Mag Cases feature a built-in tension spring to securely hold magazines of various sizes. For two magazines on the same carrier" you can remove the belt clip and place two Single Mag Cases side-by-side on Their Dual Rail Accessory Platform (sold separately). The case can also be placed next to one of their light carriers for a combo light/mag carrier.