Uncle Mike's Quick Detachable Magnum Band Sling Swivels for Single and Over/Unders, .750-.800-Inch Diameter (Blued, 1-Inch Loop) Swivel lock spring loaded plunger A knurled, threaded sleeve Magnum split barrel band Wood screw base for buttstock Closed link Technology creates a permanent ring Bond Magnum split barrel band base mounts without tools or dismantling Fits all 16-gauge and some 20-gauge shotguns .750-.800" diameter Wood screw base for buttstock Closed Link technology creates a permanent ring bond