Borla 13-15 Audi S3 S-Type Dual Round Rolled Catback ExhaustBorla 13 15 Audi S3 S Type Dual Round Rolled Catback Exhaust BORLA(r) system has valves. System features polished T 304 stainless steel tips. BORLA(r) Cat Back(tm) and Axle Back exhaust systems feature patented straight through and multi core technology designed to unleash hidden horsepower. Increased exhaust velocity adds power, driving excitement, fuel economy, and the distinctive BORLA(r) Sound of Power respected by motoring enthusiasts everywhere.