This catback system from Greddy for the Subaru WRX / STI has been produced using the same careful engineering practices to provide your vehicle with increased horsepower, torque, and this exhaust system will enhance that flagship rumble. This exhaust system consists of 3” piping that routes to a “Y” section that is designed around the differential for an improved flow. Exhaust gases will exit a pair of mufflers with quad polished 3.5” oval tips to produce one of the best sounds out of your vehicle. Included with this exhaust system are the required gaskets and hardware to make for a ready installation. No further modifications or alterations will be needed to the rear bumper to make this unit fit.