Aluminized Steel 4 Inch Resonator Back Single Side Exit 4 Inch Cat Back, Single Side Exit, Aluminized Built from heavy duty Aluminized Steel our Installer Series performance exhaust systems offer a value price without compromising on the quality built into every component.While the seams are a major point of rust through with some budget systems our fully sealed tubing adds years to your system. Constructed to the same specifications as our top of the line Pro Series we back this line with an industry leading 3 Year Warranty.Built to Perform MB