Product Description: 2.5in. Axle-Back; High Clearance; Single Rear Exit; Race Version; T409 Stainless Steel. RELIABILITY BACKED FOR A LIFETIME - ARMOR PLUS Series exhaust systems are crafted from corrosion-resistant T409 Stainless Steel - a value-oriented material designed to protect from penetrating rust and will stand up to almost anything you can throw at it. T409 Stainless Steel tubing is easy to clean. If you're looking for a performance exhaust system with a Lifetime Warranty, this is probably the one for you.