1/2" MPT 2" long BCS Temperature Sensor. This sensor is permanently welded into a 1/2" MPT fitting, eliminating the need for a compression fitting. Although not as easy to disassemble as the straight-mount/compression fitting type of mount; these can save quite a bit of money when multiple sensors are needed that don't require frequent removal. The 2" measurement is from the face of the fitting to tip of the protection tube. The cable length measures 8' overall from the tip of sensor to end of cable and is foil shielded with a drain wire. Protection tube is 304 stainless.

An M12 quick disconnect version is very easy to make with the cable end below. 

Made with a Vishay 1% tolerance thermistor.

4" version shown.