Borla 23-24 Nissan Z 2.5in ATAK Cat Back Exhaust 4.5in Tip - Stainless SteelBorla 23 24 Nissan Z 2. 5in ATAK Cat Back Exhaust 4. 5in Tip Stainless Steel This system is a True Dual design that features a Resonator with an internal H Pipe, Polyphonic harmonizer technolgy, and SwitchFire technology. All of these features combine to provide the ATAK sound level, our most aggressive sound. It provides a more exciting driving experience without any drone.. The Merge X Pipe blends the combustion pulses from both sides of the engine