This system will fit vehicles with and without NPP. BORLA(r) system does NOT include NPP valves. System contains a Merge X-Pipe for increased power while adding a great sound and dual 4" round polished T-304 stainless steel tips on each muffler assembly for sharp appearance. BORLA(r) has exhaust technology that enables their engineers to deliver unprecedented vehicle-specific control over the acoustical note of an exhaust throughout the RPM range while retaining 100% of the power-adding capabilities of BORLA(r)â€s patented Multicore design. Called ATAK(r) (Acoustically-Tuned Applied Kinetics) this exclusive technology (U.S. patent #5 248 859) produces the highest available dB (decibel) levels in the BORLA(r) street-legal lineup and is designed for high-performance purists who prefer exhaust notes over their stereos. The focus of ATAK(r) is to pump the volume while retaining clarity of sound at the same time avoiding the drone and distortion typically found in louder exhausts. With ATAK(r) the sound output is tuned like a graphic equalizer to shape and focus sound waves for optimum high-volume output. The development of each ATAK(r) system begins with extensive study of each vehicleâ€s acoustical properties. The technology is based on custom-tuned attributes of the internal muffler cores which are calibrated on a vehicle-by-vehicle basis to deliver the most desirable sound. BORLA(r) offers Cat-Back(tm) and/or Axle-Back ATAK(r) exhaust systems for a wide variety of popular applications with more in development. This ATAK(r) system has been specifically tuned for the '05-'08 Corvette C6. Like all BORLA(r) exhaust products each system is handmade in the USA by master craftspeople and features premium high-quality T-304 austenitic stainless steel construction mandrel bending by computer numeric control (CNC) machinery to ensure maximum flow and a perfect fit and a Million-Mile Warranty.