Convert your standard mil spec AR 15, M4, M16 lower assembly to use 9mm Beretta 92 Magazines! The MAG-AD series adapters install in seconds. Boasting a last round hold open feature making them a breakthrough product and a must-have for law enforcement and civilian gun enthusiasts alike. The Stern MAG-AD series adapters are made of aircraft grade aluminum, lightweight with ergonomic design. Made in the USA Constructed from 6061 T6 aircraft grade aluminum 4140 NiB coated feed ramp Hardcoat anodized type 3 Sturdy construction Ergonomic mag release Works with any Mil-Spec AR15 lower receiver