Cummins Onan (155-3481-02 Tail Pipe/Exhaust Kit Cummins TAIL PIPE and EXHAUST KITS - HGJAB RV generator sets have a built-in USDA Forest Service approved spark arrester muffler It is necessary to equip the generator set with a tailpipe at installation Contains tailpipe, clamp and a hanger Exhaust tube connects to 1-3/8 inch Outer Diameter down tube on generator 26 Inch Tailpipe