Suit Nissan Navara D22 with YD25 engine.
Suit Nissan Navara Thai and Spanish D40 with YD25 engine.
This is one of the O'Rings required for the Cooler Assembly on a YD25 Engine.
It is common for the Oil Cooler Assembly on the side of the Engine to leak, and just replacing one of the Orings normally doesnt do the trick, it is best to replace the whole oring and gasket set.