Ford Mustang GT Varitune Complete Cat Back Exhaust Kit With Resonator Delete Pipe 15-17 PART #30065 FEATURES: Direct Bolt On 2-3/4" Cat Back Exhaust Kit For The Ford Mustang Kit Includes BBK Varitune Mufflers With An Internal Power Valve That Allows Fine Tuning of Sound and Power Levels Change From One to Three Chamber Muffler by Turning a Wrench Large 2.75" Mandrel Bent Tubing for Maximum Flow 8-10 Decibel Range Difference Kit Includes BBK Resonator Delete X Pipe As Shown 4" Stainless Steel Tips VEHICLE FITMENT: 2015-2017 Mustang GT Coupe Does Not Fit Convertible Models One-of-a-Kind Adjustable Axle Back The BBK Varitune Cat Back Exhaust Kit for 2015-2017 Mustang GT 5.0L offers full tuning ability with BBK's patented adjustable power valve. That's right, these unique systems come complete with two patented tune-able Varitune performance mufflers engineered with high-flow, direct fit 2-3/4" tubing and hardware for an easy bolt on installation. Each system also includes a pair of stylish 4" stainless tips to deliver good looks in addition to maximum performance. Adjustable Mufflers? These American designed and built performance mufflers are the first of their kind in the aftermarket fully adjustable performance mufflers that can be adjusted for sound and horsepower by simply moving the adjustment screw in or out from underneath the car! BBK Varitune performance mufflers utilize a unique internal power valve. When in the closed position the valve blocks the exhaust flow, forcing it through all three chambers of the muffler for a classic mellow sound. When in the open position, the valve opens the exhaust flow allowing it to take the path of least resistance, acting more like a straight-through muffler for an aggressive throaty exhaust note. Installation BBK Varitune exhaust kits are engineered and built with large 2-3/4" CNC mandrel bent aluminized tubing for unrestricted exhaust flow. These Mustang Axle Back kits are direct fit and include all hardware required for a true bolt on installation. No cutting or welding is required.