Suitable for use as a Coolant Temperature Sensor (CLT) on all vehicles, or as an Intake Air Temp Sensor (IAT) on naturally aspirated vehicles. These are the proper GM-style sensors for use with the MegaSquirt line of ECUs and come with the weatherproof connector and two crimp pins.

The threads are 3/8" NPT pipe thread - note that isn't an actual 3/8" outer diameter but a pipe thread size based on pipe inner diameter.