The Versacarrier® Magazine Holder is a revolutionary design for a spare magazine pouch. It uses the spring space that is left inside of the magazine after full capacity for retention.The Versacarrier® is held to the magazine by actually inserting it as if it were another round. Although this is the case, it does not cause you to lose any rounds as it works off what little spring space is left after a magazine has reached full capacity. Easy on / off non bulky design with adjustable tension. Made in the USA.