IMPREZA WRX STI 02-07 3.00" N1 CATBACK EXHAUST MUFFLER Fitment: 2002-2007 Subaru Impreza WRX/STI (Sedan Models) Catback Exhaust System!! SUS-304 Stainless Made Steel with Polish Finish. 3" Pipe design 7" round cansiter with 4" N1 Tip with removeable silencer. Designed for high performance as well as meeting sound level standards. With its deep throaty tone, it echoes its racing lineage. Optimize torque in the low to mid speed range Racing spec design to gain more horse power, faster response, averaging 15-20 Extra HP. PROFESSIONAL INSTALLATION IS HIGHLY RECOMMENDED. NO INSTALLATION GUIDE IS AVAILABLE.