Made with a high-quality rubber bulb pump and 5/8" outer diameter fuel hose, arrows are marked on the valve body to show the direction of fluid flow to prevent fuel from returning to the tank. The boat fuel line uses high sealing material fully compatible with ethanol-blended ...Made with a high-quality rubber bulb pump and 5/8" outer diameter fuel hose, arrows are marked on the valve body to show the direction of fluid flow to prevent fuel from returning to the tank. The boat fuel line uses high sealing material fully compatible with ethanol-blended fuels and engineered low permeation material, with the advantages of anti-aging, anti-hardening, and avoiding fuel evaporation.