Each set uses mild steel, smooth flowing, CNC mandrel bent tubes, that are hand-welded to ensure each pair is identical to the next. Hedman's unique, gasketless ball and socket collector design allows your vehicle's exhaust system to bolt up, even if it is not perfectly aligned with the header collectors. These headers are uncoated, and ship from the factory with a temporary black paint that will burn off when submitted to normal operating temperatures. Each set includes a pair of gaskets, header flange bolts and collector bolts. No collector gasket is needed.