Cylinder: Replacement choke tube for Winchester model Mossberg 500, Browning Invector, Weatherby and Savage shotguns chambered in 20 gauge ammo. .620 Diameter Improved Cylinder Tube: Replacement choke tube for Winchester model Mossberg 500, Browning Invector, Weatherby and Savage shotguns chambered in 20 gauge ammo. .610" Diameter Modified Cylinder Tube: Replacement choke tube for Winchester model Mossberg 500, Browning Invector, Weatherby and Savage shotguns chambered in 20 gauge ammo. .600" Diameter Mfg: Carlsons
