Borla 11-12 Mustang Shelby GT500 2dr 5.4L 8cyl Aggressive ATAK Exhaust (rear section only)Brand Borla Part Number 11799 Category Exhaust, Mufflers & Tips Catback Condition Brand New Original Manufacturer Packaging Features bright chrome on 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 basis to deliver the most desirable sound. This is our most aggressive sound. Even though the sound on