GrovTec GTSW40, Two Piece Barrel Band, Black Oxide Finish, Black, Includes (2) GT Locking Swivels, (1) .420 - .470 Clip On Stud, (1) Wood Screw Stud, (2) Spacers GTSW40 No swivel stud on your shotgun forearm? Want to mount a sling on your lever action rifle's magazine tube? GrovTec's GT Barrel Band Swivel Sets are your answer. Their one and two-piece barrel band sets fit almost any firearm from a .22 rimfire magazine tube of .420" diameter up to shotgun barrel with a .900" diameter.