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.