Part# 140075 is the more Aggressive “S-Type” Cat-Back(tm). The mellow “Touring” Cat-Back(tm) exhaust is part# 140053 Borla 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 #140075, is custom designed by Borla engineers for the 2.5L turbocharged 4-cylinder engine with automatic and manual transmissions. Winning on racetracks around the world has given Borla 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 XR-1 patented technology utilizing 3″ tubing that exits with a super looking Borla logo embossed 4″angle 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 XR-1 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. Add a Borla header (#17217) for even more performance. Borla 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 street products carry the famous Borla written million-mile warranty.