This KAC Carbine Receiver End Plate integrates a QD Sling Swivel Socket into either side for ambidextrous use. The QD Sockets are Non-Rotational, meaning they will not allow an installed swivel to spin freely within the socket, but instead give it a limited range of movement. Comes with lock ring only (push-button sling swivel not included). Compatible with both SR-15/AR-15 and SR-25 platforms with a carbine type receiver extension. Mfg: Knights Armament