This locking fuel filler cap seals the tank opening on the host tractor. It is part of the fuel delivery system, preventing contamination and fuel loss during operation. The cap includes a set of keys for locking and unlocking. A worn or missing cap allows dirt and moisture into the fuel, which can clog filters and damage the injection system. The cap is manufactured by AGCO to match the original sealing geometry, ensuring a proper seal against the filler neck.