Borla 16-18 Chevy Camaro V8 SS AT/MT ATAK Rear Section Exhaust w/o Dual Mode Valves Ceramic BlackThis system features the aggressive ATAK(r) sound with no drone inside the vehicle. The 2. 75" diameter (1 tail pipe on each side is 2. 5") system has dual tips on each muffler assembly and will fit vehicles with Dual Mode Exhaust (NPP) valves but it does NOT include NPP valves. It may be used with the dual tip lower bumper cover to convert a single, split rear exit to a dual split rear exit. By adding Borla(r) X Pipe with Mid Pipes part number 60607