GrovTec two-piece band attaches to tube magazines of .420"-.470" diameter without dismantling gun. Set also includes .75" rear swivel stud with spacer, Allen wrench and one pair GT Locking Swivels.Our 2-piece barrel band sets fit almost any firearm from a .22 rimfire magazine tube of 0.42 inches diameter up to shotgun barrel with a 0.9 inches diameter.