Non Locking Fuel Filler Cap=Non-Lock Fuel Cap w/ Discriminator. [50 State Emissions], [22 GALLON MIDSHIP FUEL TANK] Or [52 Gallon Rear Fuel Tank], [22 GALLON MIDSHIP FUEL TANK] Or [52 Gallon Rear Fuel Tank] Without [52 and 22 Gallon Dual Fuel Tanks], [22 GALLON MIDSHIP FUEL TANK] Or [52 Gallon Rear Fuel Tank], Without [52 and 22 Gallon Dual Fuel Tanks], [52 and 22 Gallon Dual Fuel Tanks], [Non Locking Fuel Filler Cap] OR [NON-LOCK FUEL CAP W/ DISCRIMINATOR].