Uncle Mike's Quick Detachable Magnum Band Sling Swivels for Single and Over/Unders, .700-.750-Inch Diameter (Blued, 1-Inch Loop) The unique quick detachable (QD) design stops the metal swivel body from contacting the gun The close Machining tolerances provide smooth and silent operation Magnum split barrel band base mounts without tools or dismantling Magnum split barrel band base mounts without tools or dismantling Fits some 20-gauge shotguns .700-.750" diameter Wood screw base for buttstock Closed Link technology creates a permanent ring bond