CARLSON’S.670 DIAMETER EXTENDED TURKEY CHOKE TUBE•For: Remington 12 ga.•Diameter: .670•Extend approximately 1" from the end of the barrel •Matte blued 17-4 heat treated stainless steel •1.050" parallel section produces the optimum pattern with your shotgun •NOTE: Do NOT use steel shot larger than #4 in these choke tubes