a.double wall (cut to length & in coil) O.D.:4.76mm,6.00mm,6.35mm,8.00mm,9.53mm,10.00mm Coating: copper, white zinc, yellow zinc. b.Single wall(in coil) O.D.:4.76mm,6.00mm,6.35mm,8.00mm,9.53mm,10.00mm Coating: copper, white zinc, yellow zinc.