4 - inch constant - diameter pipes with Straight - thru muffler. Cuts back pressure up to 81 Percent. Retains stock catalytic converter. 5 - inch Chrome or Cerakote Black tip Includes Power Elbow. F - 250 F - 350 PICKUPS and EXCURSIONS Banks 4 inch Monster turbo - back stainless steel exhaust features streamlined turbine - outlet pipe, intermediate pipe and tailpipe all formed of stainless, heavy - wall tubing with constant - diameter bends to maximize flow, lower exhaust gas temps and slash backpressure up to 81. (Available with or without a cast, large - bore Power Elbow housing). Designed to retain stock catalytic converter. The polished - stainless Monster muffler features a straight - through 4 inch diameter flow - path with a Banks - designed expansion chamber to dissipate the annoying mid - range exhaust drone that affects most straight - through designs. The muffler utilizes spun ceramic, very - high - temperature packing, more than doubles stock exhaust flow, and delivers an authoritative - but never intrusive - exhaust sound. And the 5 inch polished rolled - edge tip has an adjustable clamp for positioning on tailpipe. Get it in your choice of chrome - over stainless or high temp black (And to help keep it looking good, there's a 12 inch air gap to keep heat from tarnishing the finish). Important Some vehicle configurations require an extension kit for proper fit. Pickups other than standard - cab long - bed or extended - cab short - bed require Exhaust Extension Kit. Extended Cab Long Bed 53517 required, Crew Cab Short Bed 53516 required, Crew Cab Long Bed 53518 required.