Finally a fuel dispenser that will not leak, shuts off when you tank is full and can be used to transport fuel, legally. This dispenser has a unique nozzle that is spring loaded with a seal (replacement seals are available) that keeps the jug completely sealed. Nothing gets in or out. When you are ready to dispense you place the nozzle on the fuel filler tube and press the jug down. This action opens the nozzle and the vent inside the nozzle creating a sealed fluid and air transfer. The fuel goes into the tank and the air transfers into the jug. When the fuel reaches the nozzle the vent is closed and the fuel stops flowing. Remove the jug and the nozzle closes. You can also buy standard caps and nozzle adapters for street cars and tanks with small filler tubes.