The GrovTec Two-Piece Barrel Band Swivel Set has an Allen wrench for installation, a .75 wood screw swivel stud for the butt stock and a two-piece magazine band, sold by diameter .8-.85 for this set. Best of all, there are two locking swivels with a 1 loop that have the easy-adjust thumbscrew for security and function. Install the best locking swivel sling loop you can get to make your next trip to the field a real joy.