Stainless Works Catback M12CB3HDR 2011-14 Mustang GT/ 2011-2012 Shelby GT500 3" 304 SS Catback Dual Exhaust with retro chambered mufflers and mirror polished 304 SS slash cut conical double wall tips. Includes hangers and clamps and is designed to fit to Stainless Works Performance Connect headers which retains a full 3" system. 304 stainless steel, 3" exhaust, chambered round mufflers, tips 2011-14 Mustang GT/ 2011-2012 Shelby GT500 3" 304 SS Catback Dual Exhaust with retro chambered mufflers and polished tips. Includes hangers and clamps and is designed to fit to SW Performance Connect headers which retains a full 3" system. Exhaust System