Bg diana grade 12ga.Inv plus extended choke tube imp.Mod.
-Stainless steel with titanium nitride finish
-Longer choke taper inside Invector-Plus choke tubes for use with back-bored barrels
-Stainless steel barstock is heat treated prior to machining
-Titanium nitride surface 72HRC hardness for excellent wear & reduced plastic buildup
-Absolutely perfect concentricity for superior patterning
-Extends beyond the barrel for easy removal and installation