Since mid-1964, Mustang has always been about muscle, looks, and loads of customization options. Borla?s lineup for the Mustang Shelby GT500 lives up to this legacy, with systems to meet a wide variety of performance goals and budgets. For?soundaholic Mustang GT drivers who won?t settle for anything less than unbridled performance with a pure, aggressive pony car growl, Borla offers a Cat-Back (PN140500) and Axle-Back system (PN11830), each featuring Borla?s S-Type mufflers. Both are also available with Borla?s more aggressive ATAK mufflers (PN140501) and (PN11831). Responding to the high-output exhaust needs of the Shelby GT500, Borla engineers developed these specially-tuned systems with performance and great sound in mind. All of Borla?s Shelby GT500 systems feature high-quality T-304 austenitic stainless steel construction, ultra-smooth mandrel-bent 2.5? tubing, flawless welding from master craftsmen, mirror-polished 4? diameter angle-cut 12? dual T-304 stainless steel tips with rolled edges, and an unrivaled Million-Mile Warranty. From the dimensions and perforation patterns of the inner cores to the amount of composite filament packing, all specifications of Borla mufflers are tuned on a vehicle-by-vehicle basis for an optimum blend of performance and sound. Combined with distinctive motorsport styling, easy bolt-on installation and enhanced fuel economy, the world?s most winning exhaust continues to lead the industry it founded over 40 years ago. Best of all, its covered by Borla's million-mile warranty.