New aftermarket sending unit includes the O-ring. Fits 2WD 3/87 thru 91 from chassis number 25-H082434, but this unit can be used on all 2wd models from 1980 thru 1991. The earlier version, part number 251919051E, is no longer available, which is not a bad thing. The later version has a shorter arm and reads more accurately than the long arm early version.
If you want the higher quality VW factory o-ring please click here.
Ref ID: 251919051K