The OPW 11A-B20 nozzle is UL and ULC Listed for use in gasoline, diesel, and up to B20 (20% Biodiesel). See specific listings. Prevents gasoline spills in prepay or card-lock systems utilizing OPW's unique No Pressure – No Flow Device. The nozzle cannot be opened until the pumping system is pressurized, and closes automatically when the pressure is removed. (11B Series Only) Prevents consumer from jamming the nozzle in an open position – Blocker on lever guard. FlowLock allows nozzle to shut-off when falling out of a vehicle, and tipped up limiting spillage and unsafe conditions.