What is this O Ring for?

[Mangudai]

CourtesyParts :: [15068F] SEAL-O RING - 240SX (S14) 1995-1998 (http://www.courtesyparts.com/15068f-seal-ring-240sx-s14-1995-1998-p-134395.html?cPath=3690_7647_9160&)

I ordered it when I was buying my parts for a tune up and I don't even know where the hell I'm suppose to put it.

[tgd89]

Well looking at the parts diagram on courtesy, it seems to be the o-ring between oil stud and where the filter bolts to.

150 Lubricating System :: Engine Mechanical :: Genuine Nissan Parts :: 240SX Parts (S14) 1995-1998 :: CourtesyParts.com (http://www.courtesyparts.com/240sx-parts-s14-1995-1998/genuine-nissan-parts/engine-mechanical/150-lubricating-system/-c-3690_3691_3692_3706.html)

[Mangudai]

Ah I see now. I should have been able to figure that out. Thanks.