The Desert Tech QMAG-53 is a 53 round magazine and is compatible with the Quattro-15 lower receiver. The Quattro-15's 53 round magazines give patriots the ability to carry a 210 round loadout with only 4 magazines instead of 7. That's 50% less reloads and an 8% lighter loadout weight. The QMAG-53 is a single spring, single follower design which allows for unrivaled reliability, especially during suppressed fire.