GrovTec US .645-.660in Relieved Top 2 Piece Barrel Band Swivel Set Black. Want to mount a sling on your lever action rifle's magazine tube? Their 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 .420in diameter up to shotgun barrel with a 1.025in diameter. Specifications for GrovTec US Two Piece Barrel Band - Swivel Sets 1in Loop: Manufacturer: GrovTec US Color: Black Gun Model: Universal Package Contents: GrovTec US Two Piece Barrel Band - Swivel Sets 1in Loop GrovTec US GTSW41: .645-.660in Relieved Top 2 Piece Barrel Band Swivel Set Black