Now you can add sling swivels to your favorite pump or auto without altering your shotgun. Uncle Mike s Magazine Cap Swivel Sets have a factory magazine cap with the swivel base already installed. Just unscrew the factory magazine cap and replace it with the new cap. For the buttstock a 3/4 wood screw swivel base is included along with two Super Swivels.Includes replacement magazine cap with swivel base 3/4 wood screw buttstock swivel base and two Super Swivels.