The 4 in. Monster exhaust system flows up to 122 percent better than stock and virtually eliminates backpressure. Banks streamlined 4 in. turbine outlet pipe with provision to retain stock catalytic converter, intermediate pipe(s) and tailpipe are formed of stainless, heavy-wall tubing with constant-diameter bends to maximize airflow and lower exhaust gas temps. Banks replaces the factorys restrictive muffler with a polished-stainless Monster muffler featuring a straight-through 4 in. diameter path that flows up to 129 percent better than stock.The Banks-designed expansion chamber dissipates the annoying mid-range exhaust drone that accompanies most straight-through mufflers. Monster muffler utilizes spun ceramic, very-high-temperature packing and delivers an authoritative - but never intrusive - exhaust sound. And the 5 in. 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, theres a 1/2 in. air gap to keep heat from tarnishing the finish) Monster Exhaust System, Single Exit, Black Round Tip for use with 2004-2007 Dodge 5.9L 325hp, SCLB/CCSB Standard Cab Long Bed or Crew Cab Short Bed