Attwood fuel tank fittings and hose fittings are suitable for use with leaded, unleaded, ethanol blended and alcohol-blended fuels. Unless otherwise specified, threaded fittings have 1/4" male NPT threads; barbed fittings fit 3/8" or 5/16" I.D. hose. Clamps are not included. Use fuel compatible thread sealant on all threads.