Small metal coolant flange for the end of the cylinder head.
Universal model with 2 tapped M10x1.0 holes and supplied with a blanking plug to suit engines with one or two sensors.
Flange is now sealed with an o-ring as opposed to a gasket.
Caddy 1 with JK Engine
All T3 Diesel and turbo Diesel models up to WV2 ZZZ 25 Z KH 064 850 (they swapped to plastic after this, January 1989)
Iltis with TD "1C" engine.
Please be aware that in our workshop we have had quite a few instances of faulty readings from the coolant temp sensors from engines with the metal coolant housings fitted, probably the reason why VW swapped to the cheaper to produce plastic housings and running dedicated earth wires to sensors.
We have remedied the situation by running a separate earth wire to the flange and earthing the housing properly, this gives more reliable temperature gauge and glow plug plug duration.