Use this exhaust when you're driving your 1999 - 2004 Ford F - 250 or F - 350 Super Duty. It's great for drivers who live in dry areas and want to improve their vehicle's performance without spending a fortune. The tubing is made of heavy - gauge aluminized steel and is mandrel - bent. It has a 4 - inch single - side design and part numbers ending in P and PLM have a 1 - year warranty.