Part 140075 is the more Aggressive S - Type Cat - Back(tm). The mellow Touring Cat - Back(tm) exhaust is part 140053 BORLA(r) Performance once again leads the industry with a high flow performance exhaust for the hot Subaru WRX and WRX STI. This Cat - Back(tm) system, BORLA(r) 140075, is custom designed by BORLA(r) engineers for the 2.5L turbocharged 4 - cylinder engine with automatic and manual transmissions. Winning on racetracks around the world has given BORLA(r) a leg up on the competition with trickle down technology from the world's fastest cars. The unique design is a direct bolt - on fit that meets all emission requirements. The system has shown significant flow and performance improvements by virtue of BORLA(r) XR - 1(r) patented technology utilizing 3 tubing that exits with a super looking BORLA(r) logo embossed 4angle cut, rolled edge, single round polished T - 304 stainless steel tip. More flow means more power, and if you tune this turbocharged super import, that flow will simply allow even more power. When you get a close look inside this muffler, you can see the patented BORLA(r) XR - 1(r) multi cores - - that look says total performance. Increased fuel mileage is an added benefit. And, one more thing, it has a great sound, too, but then you've come to expect that from BORLA(r). Add a BORLA(r) header (17217) for even more performance. BORLA(r) Performance Industries, the original pioneers of high quality T - 304 austenitic stainless steel (superior to T - 409 or aluminized steel) free flow exhaust utilizes its patented award and race winning technology to deliver quality, sound, performance gains and enhanced fuel economy all with an easy bolt - on installation. All BORLA(r) street products carry the famous BORLA(r) written million - mile warranty.