The Soul Performance 991.1 Carrera valved exhaust system was designed to deliver both performance but also a certain level of professionalism. With the valves open, the exhaust gases exit through an unrestricted path offering you, the enthusiast, a wonderful flat six symphony. Need to keep it a bit more mild mannered on your way to a client dinner or pulling in the driveway late at night? Not a problem whatsoever. Keep the valves closed and enjoy the a refined low tone as the factory side mufflers do their job quite well. Own a PDK? Worried about drone? Don't. The Soul Performance Exhaust for the 991.1 PDK will not leave you disappointed or frustrated. Street Headers are built around free flowing HJS HD 200-cell catalytic converters and long tube runners for maximum gains in power, throttle response, and flat-six engine tone.