Stern Defense AR-15 Mag-AD Magazine Adapter Features The Stern Defense Mag-AD Magazine Adapter installs into a standard mil-spec AR-15 M4 or M16 lower receiver in seconds instantly enabling compatibility with Smith and Wesson M&P .45 ACP magazines. This gives AR-15 owners a way to run a pistol caliber upper without needing a dedicated magazine well or lower built specifically for that purpose. Machined from aluminum and finished in black anodize the adapter is built to withstand repeated use and the stress of cycling a pistol caliber bolt carrier group. Its precise fit keeps the magazine properly indexed for reliable feeding. A last round hold open feature built into the Mag-AD is a notable innovation for pistol caliber carbine adapters many of which lack any bolt hold open functionality at all. This feature lets shooters know immediately when their magazine runs dry speeding up reload transitions during competition or defensive use. Because it is built for the AR-15 platform specifically installation does not require any permanent modification to the lower receiver. The Stern Defense Mag-AD Magazine Adapter is a practical upgrade for sale at GrabAGun for AR-15 owners wanting .45 ACP versatility. Stern Defense AR-15 Mag-AD Magazine Adapter Specifications Manufacturer: Stern Defense Model: Mag-AD Caliber: .45 ACP Compatible Hosts: AR-15 Material: Aluminum Finish: Black Anodized Available At: GrabAGun