S6 C6 BXA - oil gasket number

[Szwagier]

Hi. I’m sealing my engine and replacing all possible gaskets. However, during disassembly, I found a gasket whose number isn’t listed in ETKA. Specifically, it’s number 4 in the photo (under cylinder block). Can anyone help me with the OEM number?

[audis6]

https://forums.audirevolution.net/t/07-s6-coolant-in-oil-complete-engine-teardown-with-pictures-re-stored/16384/2

079-103-121-AC

O-ring on ebay