Stern Defense Mag-AD9 Magazine Adapter Features The Stern Defense Magazine Adapter converts a mil spec AR-15 M4 or M16 lower to accept Glock pattern 9mm and .40 SW magazines letting builders reuse magazines they already have on hand. A 4140 NiB coated feed ramp smooths feeding across magazine generations and the ergonomic mag release keeps manipulation fast and intuitive under a mil spec lower s normal controls. Installation takes only seconds and requires no permanent modification so the adapter can be swapped in or out as a build s needs change. The last round bolt hold open feature keeps the carbine behaving like a standard AR-15 even while running pistol caliber magazines. Built from 6061 T6 aircraft grade aluminum and hard coat anodized for durability the adapter is designed to survive the same hard use as the rest of the rifle. Every other component of the host build apart from the bolt and barrel stays completely stock which keeps parts sourcing simple. The design requires a 9mm or .40 SW specific barrel along with a Glock cut bolt to complete the conversion. This adapter is a straightforward way to build a reliable magazine compatible 9mm AR-15 carbine around hardware a shooter may already own. Stern Defense Mag-AD9 Magazine Adapter Specifications Manufacturer: Stern Defense Model: Mag-AD9 Compatible Hosts: Glock AR-15/M4/M16 Mil Spec Lower Caliber: 9mm / .40 SW Color: Black Material: Aluminum Finish: Hard Anodized Available At: GrabAGun