While both the UBR® and STR® come with TYPE 1 push-button QD swivel sockets pre-installed on the left side of the stock, this Sling Mount Kit TYPE 2 can be installed on the opposite side to add additional push-button QD Sling Swivels or our own Magpul® QDM. Additionally, for running ambidextrous sling swivels on the SGA®, MOE® Rifle, MOE® Fixed Carbine, MOE® AK, Zhukov-S, Hunter 700, and Hunter X-22 Stocks, this TYPE 2 Kit must be utilized in conjunction with the optional TYPE 1 Kit. Heavy-duty black phosphatized steel construction easily installs with the UBR or STR's original hardware, or with the hardware included with the TYPE 1 Kit. Swivels not included. Made in U.S.A.