Stepped 1-3/4" to 1-7/8" headpipes header system 4" muffler body and matching end cap Features TIG welding, 18 mm O2 bungs with 12 mm adapters Partial heat shields that cover the headpipes Made in the U.S.A.. Exhaust 2:1 Super Bike SS with 4" Muffler M8 Softail 18-23