-Accepts any push-button QD sling swivel as well as the Magpul QDM -Durable steel construction -Case hardened & finished with Melonite™ for extreme resistance to wear & corrosion -Works with both mil-spec & commercial-spec carbine receiver extensions (buffer tubes) Note: The ASAP QD is NOT compatible with A1/A2 fixed stocks as well as any other similarly mounted stock such as the Magpul PRS®, UBR®, & MOE® Rifle Stocks.