Jones Exhaust Flowpack Muffler JFP300 3.00 Inch Inlet / Outlet Jones Exhaust Flowpacks MufflerJFP300 3.00 Inch Inlet / Outlet They are 5.00 round, with a 13.00 shell length and 19.50 overall. 16 Gauge Aluminized Steel Baffled Muffler produce a sound that is powerful and aggressive. Both durable and economical, Fits a 3.00 Inch Exhaust Pipe