Borla 23-24 Nissan Z 2.5in S-Type Cat Back Exhaust 4.5in Tip - Stainless Steel TipsThis system is a True Dual design that features a Merge X Pipe and Polyphonic harmonizer technology. All of these features combine to provide the classic S Type sound level and the Borla(r) no drone guarantee. The Merge X Pipe blends the combustion pulses from both sides of the engine for improved performance and a custom sound. Borla(r)'s Polyphonic Harmonizer Technology utilizes patented units that contain pipes of different diameters and lengths to