I use one as a crush washer for the oil drain plug. I think you get two because this filter has other applications (vehicles) that possibly require that washer.

Psst - what kinda oil did you use? shhhh

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1985 300 D T - Rauchsilber (Smoke Sliver Metallic) with MB Tex Quartz 155 = Cream interior - 320K and counting!

1999 E300 TD - Silver - Just got her 3-13-15 !

the 2nd '83 300SD - Brown Metallic - traded away

1985 Limo Diesel aka "Stretchy" - Sliver - Blue Int - Sold but still in Athens

1983 300SD - Brown Metallic - Sold April 2008

1982 300 D T - Royal Blue with Tan interior - Sold