Fitting fuel tank apertures of 37mm in diameter and larger. The 20 litre Tuffjug with its unique dry-break coupling is the perfect container to transport liquids in. It will enable a safe and non-drip filling of the vehicle and will also stop the filling action when the fuel tank is full. In fact you will be able to turn it upside down and no fuel will come out until you compress the nozzle. Very sturdy construction. Made square to maximise storage areas. Wide-mouth design for easy pouring of additives and observing fuel level when filling Heavy-duty body with 5-gallon capacity Spill-proof, self-sealing nozzle automatically pours and shuts off as fuel level in tank fills to end of nozzle.