This Axle-Back system has Dual Tips on each muffler assembly and will fit vehicles with Dual Mode Exhaust (NPP) valves but it does NOT include Dual Mode Exhaust (NPP) valves. It may be used on vehicles that came from the factory with singe tips but you MUST change the rear bumper valance to accommodate the dual tips. Adapter Kit 60605 can be used to add NPP valves to this system. The system delivers the aggressive ATAK® sound with no drone inside the vehicle. System features a 2.25" diameter inlet,1) 2.5" tail pipe and 1) 2.75" tail pipe, and dual 4" round polished T-304 stainless steel tips on each muffler assembly. BORLA® ATAK® (Acoustically Tuned Applied Kinetics) technology is designed for high-performance purists who prefer exhaust sound over their stereos. ATAK® equipped exhaust systems deliver the highest available dB (decibel) levels in the BORLA® street-legal line-up... and unlike inferior brands that lose significant sound quality at higher volumes, ATAK® is tuned like a graphic equalizer to shape and focus sound waves for optimum high-volume output. ATAK® 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. The power of BORLA® Multicore® technology, with the sound of vehicle-specific acoustic tuning. 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.