Header Type: Long Tube / Full Length. Primary Diameter: 1-7/8 in. Collector Diameter: 3 in. Head Flange Thickness:3/8 in. Pipe Thickness: 16 gauge (1.5mm). Material: 304 Stainless Steel. Excellent quality and durability to improve vehicle performance. Full length design for power gain from mid to high RPM range. Fully mandrel bent tubes made of high quality 16-gauge 304 stainless steel. The flange is flattened by a hydraulic press for precise and leak free sealing. Head flanges laser-cut from high quality 3/8-inch thick steel plates. All joints are golden color TIG brass style welded to prevent cracking and wear. Flanges chrome plated for corrosion resistance. Polished surface for extra protection against rusting. The accessories in the photos are included. No instructions provided; professional install recommended.