Stainless Steel 1 3/8" tubing, Tig welded with thick mounting flanges - fully welded internally. The 3-bolt muffler flange is centered, flange is at the 1:00 position and features oval holes for muffler alignment. May be used with heater boxes or J-Pipes. Complete with aluminum flex hose, gaskets and hardware. Fits 3100 / 3102 / 3767.