For the person who is looking for a true dual crossmember-back exhaust system with an moderate to aggressive exhaust tone. With an easy fit in mind, these systems are constructed from 16-gauge mandrel-bent stainless steel tubing with a built-in H-pipe crossover, a pair of specially selected Super 44 Series mufflers and includes all hangers and hardware necessary for installation. The American Thunder systems deliver a moderate to aggressive interior and exterior tone and are best suited to the enthusiast who wants their performance to be heard. Like all Flowmaster exhaust systems, the benefits include improved throttle response, power and mileage. If you prefer Aluminized steel construction, check out optional system# 17129.