Use this exhaust system when you're looking to enhance your daily commute or for track days. It's perfect for car enthusiasts who want to boost their vehicle's performance and sound. The main piping is 2.5 inches in diameter, and it has 4 - inch polished welded - on double - wall angle - cut folded - edge tips. It's suitable for Scion FR - S, Subaru BRZ, and various Toyota models from specific years.