These patented BBK Performance Varitune mufflers are the first of their kind in the aftermarket, fully adjustable performance Mufflers that can be adjusted for a louder or quieter sound and horsepower by simply moving the adjustment screw in or out from underneath the car with a wrench!These mufflers are manufactured with 439 stainless steel, in 2.5, 2.75 and 3.0 and with various offsets to fit most aftermarket and OEM applications.These are 2.75 in. offset/offset Mufflers that are designed to fit many car and truck applications including most Ford Mustang applications.