Fiberglass wet exhaust muffler is designed to reduce the noise of gasoline & diesel inboard marine engines. Muffler Vernatone Round 3 in. Inlet/Outlet | Centek 1000104 Centek Vernatone round muffler Significantly reduces engine noise on inboard boats Fiberglass construction For use with 3 in. inside diameter marine exhaust hose 3 in. hose inlet & outlet 25.84 in.overall length 7.07 in. diameter For above waterline use only Good sound rating For shorter 3 in. model see P/N 1000145