GrovTec US .645-.660in 2 Piece Barrel Band Swivel Set Black. Want to mount a sling on your lever action rifle's magazine tube? Our GT Barrel Band Swivel Sets are your answer. Our 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 .900in diameter. Specifications for GrovTec US .645-.660in Relieved Top 2 Piece Barrel Band Swivel Set: Manufacturer: GrovTec US Color: Black Gun Type: Shotgun Gun Model: Universal Package Contents: GrovTec US .645-.660in Relieved Top 2 Piece Barrel Band Swivel Set GrovTec US GTSW45: .645-.660in 2 Piece Barrel Band Swivel Set Black