Convert your standard Mil-Spec AR 15, M4, M16 lower assembly to use 45 ACP M&P 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 enthusiasts alike. 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 all generations of M&P magazines Works with any Mil-Spec AR15 lower receiver