Coolant Temperature Sensor Green 4 pin. This is the coolant temp sensor for most later TDIs, including PD engined A4 chassis cars. Check your car before ordering, early cars (98-00) use the blue sensor instead. A4 ALH models.

Look at your connector to be sure- the blue sensor uses a rectangular 4 pin connector.
The green sensor (and very early black sensor, which the blue replaces) uses a round 4 pin connector.

Includes one temp sensor seal and clip (not shown).