The 556 Single Mag Insert comes standard with our proprietary MP2 allowing secure retention of nearly all 556 magazines (including most 5.45x39 magazines) without the need for bungee cords, buckles, or hook and loop flaps. The MP2s positive click-in retention provides audible and tactile feedback and delivers a smooth draw without impacting the ability to quickly reindex partial magazines during tactical reloads. The Single Mag Insert MP2 is also removable, allowing the operator to place a radio, laser range finder, or medical kit within the enclosed space.