Flowmaster's American Thunder cat-back exhaust system for the 2007-2013 GM 1500 trucks is perfect for the person looking for moderate to aggressive sound levels both inside and outside of the truck, with all of the performance benefits that you would expect from Flowmaster. This bolt-on DOR/DOS (Dual Out Rear or Dual Out Side) emissions-legal system is for Extra Cab/Standard Bed and Crew Cab/Short Bed models only, with the 5.3L gas engine (and 07-08 4.8L) and features a stainless steel Super 40 Series muffler and dual mandrel bent 2.50 in. stainless steel tailpipes. The system is finished off with polished 3.50 in. double wall stainless steel tips. The exhaust system is covered by Flowmaster's Lifetime Limited Warranty. Designed for an easy fit, this system includes all necessary parts and hardware for installation.