The AR/MCX Stock Adapter provides a modular solution for mounting Picatinny-style stock attachments (such as the SIG MPX folding stock) in place of an AR15 style buffer tube for firearms that don't mechanically require the tube for buffer spring operation.AR/MCX Picatinny Stock Adapter Without FlangeTwo-part kit with externally-threaded adapter plug and rail sectionSecured with hex-socket bolt and lock washerCompatible with threaded buffer socket applicationsModular alternative for attaching stocks and accessoriesWill NOT work with standard AR15 lower and MCX upper combinationsRequires special takedown pin when used on AR15 lower receiversDesigned specifically for applications where the carrier and buffer tube do not protrude past the receiver ring this adapter offers enhanced modularity for compatible firearm platforms while maintaining secure stock attachment.