This Axle-Back system includes the AFM valves but does Not include the NPP valves. It should be used on vehicles that are Not equipped with NPP. Optional systems are listed below as well as systems with NPP and systems without AFM or NPP. BORLA Cat-Back and Axle-back exhaust systems feature patented straight-through and multi-core technology to unleash hidden horsepower. Increased exhaust velocity adds power, driving excitement, fuel economy, and the distinctive BORLA Sound of Power respected by motoring enthusiasts everywhere. 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-controlled CNC manufacturing ensures an accurate fit. Just what you?d expect from the world?s most experienced (and most winning brand. *** BORLA's C7 Corvette Axle-Back exhaust systems are covered under our Million-Mile Warranty for non-moving parts, the exhaust valves are warrantied for 3 years. Failures of original equipment AFM and NPP actuators are Not covered by the BORLA warranty***