Stepped headers merge into a true reverse-cone megaphone muffler 1-3/4" and step up to 1-7/8" before merging into the collector to increase flow and improve performance 4" muffler body with billet end cap Removable spiral-core louvered baffle included Fits forward and mid controls Heat shields included Made in the U.S.A.. EXHST RR2-1UP 06-11FXD BK