This Attwood Fuel Vent Line Surge Protector reliably helps prevent fuel spills at the pump by alerting a boater when the fuel tank is almost filled so the pump can be shut off. Once installed along the tank's vent line, this surge protector helps an automatic shot-off fuel nozzle stop pumping to prevent a fuel spill. For non-automatic shut-off nozzles, this protector produces an audible gurgling sound to alert a boater that the tank is almost full. This protector's compact polypropylene body is clearly labeled which end connects on the vent side. It is compatible with Ethanol blended fuels and it doesn't need to be mounted to the hull. It comes with 2 hose clamps and connects to 5/8-inch hose. Attwood Corporation has been an award-winning leader in engineering, testing, and manufacturing the highest quality marine products for over 100 years. We deliver safe and reliable lighting, fuel systems, water systems, seating & pedestals, swim ladders, custom upholstery, and general marine accessories that are easy to install and meet regulatory compliance.