Used to add the Dual Mode Exhaust (NPP) valves to select Borla® systems that did not have NPP valves These pipes can ONLY be used with BORLA® mufflers that have dual outlets on each end of the muffler Vehicle MUST Have Had NPP System As O.E. Equipment To Use The Adapters Installation REQUIRES Cutting Muffler Asemblies See below for additional Product Features & Benefits