Developing systems for the C8 Corvette presented Borla engineers with unique challenges, but our team was up to the challenge. Great care was taken to ensure the integrity and function of the system as well as the vehicle itself. Part number 140839BC includes both AFM and NPP dual mode exhaust valves. It features the ATAK sound level, our most aggressive sound. It provides a more exciting driving experience without any drone. It features our Polyphonic Harmonizer and SwitchFire? technology. Borla'S Polyphonic Harmonizer Technology utilizes patented units that contain pipes of different diameters and lengths to create multiple exhaust notes that harmonize to deliver a clean, rich, full-bodied sound. Completely eliminating the turbulent center intersection of a standard X-Pipe, Borla'S patented SwitchFire? design truly blends the combustion pulses from both sides of the engine for improved performance and a custom aggressive sound. Strategically placed heat shielding is included to prevent exhaust heat damage and protect your Corvette. It comes with 4" Polished T-304 stainless steel tips and is available with Black Chrome on T-304 stainless steel tips part number 140839BC or Carbon Fiber tips, part number 140839CF. The system is constructed using T-304 stainless steel and is backed by our Million Mile Warranty. Note: After installation of the Borla system, the controllers for the AFM and NPP valves in the exhaust system should be re-calibrated according to GM Document ID 5406413. Borla recommends taking your car to the nearest Chevrolet dealer for exhaust valve recalibration services.