Hand TIG-welded stainless steel construction 1-3/4" headpipes step up to 1-7/8" into the collector to increase flow and improve performance 4" diameter straight can 11" muffler body includes matching aluminum end cap Removable spiral-core louvered baffle features an aggressive sound 18 mm and 12 mm O2 ports with adapters and plugs Partial heat shields and mounting hardware included Made in the U.S.A.. EXHAUST 2:1 SS MD/SB FL17