The KNS Precision AR/MCX Stock Adapter allows the user to mount a picatinny-style stock attachment (such as the SIG MPX folding stock or brace) in place of an AR15 style buffer tube. Many firearms utilize the buffer tube attachment of the AR15 in order to mount common stocks & braces, but do not mechanically require the tube for an in-line buffer spring. For these weapons, this product offers a modular alternative for attaching stocks or other accessories.