Race Headers are for Non US or for racing vehicles. 

By understanding exhaust flow and resonance tuning, Dundon Motorsports developed this combination. The use of the the OEM center muffler and flaps allow for drone free, quiet cruising and a glorious porsche roar when on the throttle! This setup is bolt on and can be selected with or without the exhaust flaps. 
 

Weight of the system is lighter than stock by far. Stock is 86 lbs, the weight of the Race Headers and stock GT3 muffler flaps is 36lbs This is complete header flanges to the exhaust tips including ALL hardware, clamps, straps etc, a savings of 50lbs!