Hand TIG-welded stainless steel construction1-3/4” headpipes step up to 1-7/8” into the collector to increase flow and improve performance4'' diameter straight can 11'' muffler body includes matching aluminum end capRemovable spiral-core perforated baffle features an all-new aggressive soundFeatures 18mm and 12mm O2 ports with adapters and plugsFull coverage stainless steel heat shields for the front and rear header pipes includedMade in the U.S.A.Fits Dynas with mid-controls '91-'17 and forward controls '07-'17