Borla 2017-2018 Honda Civic Type-R Cat-Back ExhaustBorla 2017 2018 Honda Civic Type R Cat Back Exhaust The BORLA(r) Cat Back(tm) system for the Civic Type R is unique in the industry with an adjustable sound level. By Changing the block off plates behind the center tip you can adjust the SPL (Sound Pressure Level) to your taste. System also features BORLA(r)'S Polyphonic Harmonizer Technology which utilizes patented units that contain pipes of different diameters and lengths to create multiple exhaust