Suits: GU TB48 Motors & Y62 VK56 motors
On the GU TB48 this O'Ring is located between the metal water pipe on the drivers side of the engine and the cylinder head
It goes into the cylinder head between the number 1 & 2 intake pipes of the manifold.
On the Y62 VK56 it's located between the metal water pipe on the drivers side of the engine and the thermostat housing.
We also sell the Oring for the metal pipe that joins to the thermostat housing, available separately in our online store.