The Uncle Mike s Magnum Swivel and Stud set is made to work with the majority of pump action and semi automatic shotgun models to give you solid mounting points for your sling. It comes complete with a gas cap mount screw base mount and a pair of 1 quick detachable swivels for you to attach your sling to. Please note this set will not work with gas operated recoil shotguns or the Browning 2000 Winchester 1400 Ithaca 37 Savage 30 Sears 21 30 or Stevens pumps.