The QUATTRO-15 Magazine is a quad-stack magazine with a capacity of 53 rounds. The benefit of this configuration is the ability to carry more ammunition with fewer magazines. For example: four QUATTRO-15 Magazines can hold 212 rounds, while seven standard magazines will only hold 210 rounds. This translates to more shooting and less reloading. To overcome the issues often faced by quad-stacked magazines, the QUATTRO-15 Magazine utilizes a simple yet highly reliable single follower and a single spring design.