The MBRP 4" XP Series Turbo-Back Exhaust System is the performance exhaust of choice for the 2003-2007 Ford 6.0L Powerstroke enthusiast who needs an exhaust system that can take anything that the road throws at it. This system's rugged sixteen gauge T409 construction can be counted on to withstand everything from salt to rocks, tar to grime. We have had such success with this line that we back it with a Lifetime Warranty.