Suits: Nissan GU Patrol with TB45 EFI
This is the larger of the two O'Rings at the base of the injector where it seals into the Intake manifold. The smaller one is also available separately in our online store.
It is common for these seals to go hard and crusty over time, this can cause a vacuum leak or if the injectors are removed they can perish when trying to re-install.