This seal is in the bellhousing of all manual transmission vanagons.  If you notice transmission fluid leaking from your bellhousing or your clutch is saturated when you do a clutch job, you'll need to replace this seal.

Fun fact:  VW and Porsche used this same seal in their manual transmissions throughout the production of Beetles, Ghias, Type III's, buses, Things, 356's etc. 

Ref ID: 113311113A