The seal is marked 111801 28 40 8R 8 SOG
It looks exactly like this one:
2004 Porsche Boxster S Convertible - Transmission - Page 2
The OEM Porsche Part that I got from the dealer is:
996 301 805 00
There is quite the difference in cost between these 2 - the OEM is 3x the cost - but the photos don't do it justice as the OEM is clearly just a much more robust part.