This MagnaFlow exhaust system is perfect for car enthusiasts who want to enhance the performance and sound of their 1999 - 2004 Ford Mustang GT. Whether you're on the race track or cruising on the street, it'll give your car an aggressive edge. The main piping is 2.5 inches in diameter, and the tips are 3.5 inches. It replaces the exhaust system from near the catalytic converter on back, and is made of durable stainless steel.