Borla 05-08 Chevrolet Corvette Coupe/Conv 6.0L/6.2L 8cyl Aggressive ATAK Exhaust (rear section only)Brand Borla Part Number 11816 Category Exhaust, Mufflers & Tips Catback Condition Brand New Original Manufacturer Packaging This system will fit vehicles with and without NPP. Borla(r) system does NOT include NPP valves. System features 4" polished T 304 stainless steel tips. ATAK(r), Acoustically Tuned Applied Kinetics, technology is based on specifically tuned attributes of the internal muffler cores, which are calibrated on a vehicle by vehicle