Ecotec mild steel header with muffler and oxygen sensor fitting that fits a 2.2 and a 2.4 engine. The header is constructed of 16 ga. tubing flange is 3/8 thick and the header tube size is 1 5/8. The lengths of the primaries are 20" 18" 21" 22" long. with a 2 1/2" outlet muffler.