Its 6061-T6 mandrel bent Chrome plated aluminum Pipe W/ Tig weld connection to make the dual pipe. A very nice piece. Has all OEM emmision connections including IAT for 2002 Ram and Dakota 4.7's 3 1/2 inlet and Dual 3 1/2 Outlets with 2 3 1/2 x 8 Too Cool Filters that is washable and reusable!!! You Pick Color. Alot easier to clean with K and N cleaner.