100% Stainless Steel System Designed on in-house AWD Dynapack dyno for unparalleled performance. 4" Mandrel bent T304 Stainless downpipe smoothly tapers to 3" for a smooth laminar flow into a 3" high-flow cat. OEM style doughnut gasket enhances flexibility, durability and sealing as opposed to lower quality flex joints. All TurboXS Exhaust components feature a 5 year warranty!. The TurboXS Turbo Back and Stealth Back Exhaust Systems are available piece by piece. You can use a downpipe, cat pipe, and a midpipe to make a full Stealth Back, or add a muffler to make a Full Turbo Back Exhaust.