Borla 2017-2018 Honda Civic Type-R Cat-Back ExhaustThe 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 notes that harmonize to deliver a clean, rich, full