This is a Factory OE Bosch coolant temperature sensor which establishes fuel richness on cold start for all fuel injected Fiat and Lancia cars with Bosch L-Jet fuel injection systems.
If your FI car has a hard time holding a consistent idle, or cold starting, this could be the culprit.
Fiat and Bertone X1/9 (80-88)
Fiat 124 Spider (80-85)
Fiat 131 (80-82)
Fiat Strada (80-82)
Lancia Beta Coupe Zagato (81-82)
Original Equipment Maker
New and unused.