Pilot Motorsports PM-504 Stainless Steel Round Muffler 2-1/4" - 2-1/2" Step Cone Center In/Center Out Round muffler Outlet diameter: 2 1/4" - 2 1/2" step cone Inlet diameter: 2 1/4" - 2 1/2" step cone Length: 13" Tank Diameter: 6"