Stepped headers merge into a true reverse-cone megaphone muffler1-3/4" headpipe steps up to 1-7/8" into the collector to increase flow and improve performance4" muffler body with billet end capRemovable spiral-core louvered baffle includedincludes mounting hardwareIncludes O2 sensor port plugsHeat shields includedMade in the U.S.A.