Dee Zee’s Auxiliary Fuel Line Connector Kit turns your Dee Zee Auxiliary tank into a portable refueling station by giving you the ability to refuel your diesel fuel tank via gravity feed system. Connect your Dee Zee Auxiliary Tank (sold separately) directly to your vehicle's fuel line to refill your tank whenever needed. Diesel fuel valve must be closed during vehicle operation and only opened to gravity feed the vehicle diesel tank during stops. Continuous fuel transfer to the vehicle tank may cause check engine alarms in newer vehicles. Some cutting may be required of the OEM fuel hose.