High Flow Exhaust.  Borla engineers have designed this axle-back to deliver a significant increase in airflow from the factory exhaust system for a dramatic power improvement.Aggressive Sound. The aggressive sound of the Borla Axle-Back comes from their signature "S-Type" Stinger Mufflers. The Stinger Mufflers are manufactured from aircraft-quality T-304 stainless steel and feature a Straight-through baffled design to produce an aggressive muscle car sound.Durable Construction.   The S-Type Axle-Back a.k.a Stinger is designed to be a direct bolt onto the factory piping, and features Borla's "S-Type" mufflers. This system is made from 2.5" mandrel-bent stainless steel, and features 4" polished tips for a super-aggressive appearance.Application. The Borla Stinger S-Type Axle-Back is designed to fit the 2005-2009 GTs, 2007-2009 Shelby GT500s and 2008-2009 Bullitt Mustangs.