For the person who is looking for a complete Header-back dual exhaust system with a performance sound. This system is mandrel bent for maximum performance and includes specially selected mufflers. American Thunder 2.5 In. systems generally deliver a moderate to aggressive interior and exterior tone and are suited to the enthusiast who wants their performance to be heard. The sound level will depend greatly on the engine and level of modification. Like all Flowmaster systems, the benefits include improved throttle response, power and mileage. Designed for an easy fit, these systems include all necessary parts and hardware for easy installation.