Retaining Spring for Racing Using * Wire Dia: 2.1mm * Outer Dia: 12.5 mm * Wind ... SteelHard DrawnNon-ferrous MetalsSurface FinishZinc/ Tin/ Nickel/ Chrome Plating, Black Oxide, Color Painted, PVC/ Powder Coating, Shot Blasting, Anodizing, Plain, Polishing ...