The GrovTec Shotgun Locking Swivel Set is perfect for attatching a swivel to the magazine of most pump action and semi-automatic shotguns. Simple modification is typically all that is required. This product is not for use on Ithaca 37, Savage 30, Sears 21, Stevens pumps or Winchester 1400 or any firearm with gas operated recoil. Also includes 3/4" rear wood screw stud with spacer and two Locking Swivels.Features1 inch loopsBlack-Oxide finishAll steel construction