Virtually indestructible 100 percent stainless TorqueTubes maximize exhaust extraction, unleashing gobs of torque. Banks TorqueTubes maximize exhaust extraction and torque. Stainless steel construction never cracks or blows. Mandrel-formed tubes tune exhaust flow for maximum torque. Patented PowerPickle pulse converter maximizes exhaust extraction (see the big PowerPickle). 5/8 inch thick flanges never warp. Flanges welded both sides, then milled flat. Banks streamlined, stainless steel TorqueTubes are the industry's only parallel 5-tube exhaust manifolds for RVs. Unlike competitors who add a separate tube length to a 4-tube formation, Banks integrates five tuned-length tubes into a design that allows rotational firing of the cylinders through the exhaust, minimizing backpressure and maximizing torque. The thick, 5/8 inch flanges never warp or leak. Maximize exhaust extraction and torque. And check out that amazing PowerPickle! 5-Year Limited Warranty