Virtually indestructible 100% Stainless Steel. Mandrel-formed tubes tune exhaust flow for maximum torque. Maximize exhaust extraction. Flanges welded on both sides, then milled flat. Seamless high-velocity collector. Exclusive tuned-length parallel 5-tube design. Patented PowerPickle pulse converter. 5/8 inch thick flanges won't warp or flex. Includes Y-pipe and heat shielding.