Thermostat housing for A4 chassis TDIs, (ALH). This housing gets brittle with age and often breaks when removing to access the thermostat. Includes o-ring.
The bolts that secure this flange to the block are one use only. Replace when replacing or removing flange.
For 2004-2005 Golf, Jetta and New Beetle TDI, the BEW flange is here.