4 inch stainless constant-diameter pipes and straight-thru muffler nearly doubles flow. Lower exhaust temps. Virtually no backpressure. Rich, throaty sound. Available for F-250, F-350, F-450 & F-550 Pickup & Excursion. Monster exhaust system flows up to 91.5% better than stock and virtually eliminates backpressure. The streamlined 4 inch intermediate pipe(s) and tailpipe are formed of stainless, heavy-wall tubing with constant-diameter bends to maximize flow and lower exhaust gas temps. Banks replaces the factory's restrictive muffler with a polished-stainless steel Monster muffler, featuring a straight-through 4 inch diameter flow-path with a Banks-designed expansion chamber which dissipates the annoying mid-range exhaust drone that's so prominent in competitors' straight-through mufflers. The muffler utilizes spun ceramic, very-high-temperature packing, more than doubles the stock flow and delivers an authoritative - but never intrusive - exhaust sound. Includes a 3-1/2 inch turbine outlet pipe (T.O.P.). A huge 5 inch stainless steel tailpipe tip in your choice of polished chrome-over stainless or high-temp black sports a rolled edge. And to help keep it looking good, there's a 1/2 inch air gap to keep heat from tarnishing the finish. An adjustable clamp lets you position it on the tailpipe just right. Automatic Transmission only, for Manual Transmission use the Banks Monster Exhaust.