This system will fit vehicles with and without NPP valves. BORLA® system does NOT include NPP valves. The single 2.5" diameter Into the muffler with dual 2" out Cat-Back™ delivers the Aggressive ATAK® sound. ATAK® Acoustically-Tuned Applied Kinetics, technology is based on specifically-tuned attributes of the internal muffler cores, which are calibrated on a vehicle-by-vehicle basis to deliver the most desirable sound. Even though the sound on the exterior is uncompromising, the sound in the cabin is devoid of harsh resonance, a product of painstaking engineering and over 40 years of experience. The system features dual 4" round polished T-304 stainless steel tips on each muffler. Each system is built from premium T-304 stainless steel, superior to T-400 series knockoffs (such as 409), to give you the absolute best in performance and durability. Ultra-smooth mandrel bends ensure maximum flow & power, and precision computer numerical control (CNC) manufacturing ensures an accurate fit. Best of all, BORLA® stands behind every system with a Million-Mile Warranty. Just what you’d expect from the world’s most experienced (and most winning) exhaust brand.