Uncle Mikes magazine cap swivel set has 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 with Tri-Lock.
Specifications:

Type	Mag/Cap Swivel Set
Loop Size	1"
Color	Black
Material	Steel
Cap Size	None
Stock Material
Design
Thread Type	N/A