Use this MagnaFlow exhaust system when you're planning a long - distance grand tour or a relaxing weekend cruise in your 1984 - 1987 BMW 325E or 1986 - 1987 325ES. It's perfect for BMW enthusiasts who want to enhance their driving experience. The main piping is 2.25 inches in diameter, and the tips are 3 inches. It's made of durable stainless steel, ensuring it can handle miles of driving with ease.