aFe Power 49-04059NM ATLAS 4" Aluminized Steel Down-Pipe Back Exhaust System Constructed of 4" mandrel-bent aluminized steel tubing for maximum flow Includes a muffler delete pipe for a more aggressive sound Does not include tip Adjustable hanger to cover all models This is a "Race Only" product used solely for competition; Its use is limited to closed-course and open-course racing that is formally sanctioned by a recognized racing organization