Water Temperature Gauge and Electric Sender Unit.

It shows both Degrees Celcius and Farenheight. (100-250 F, 40-120C) It is 12 volt for use in almost all cars, trucks, buses, engines, etc.

It fits into a 52mm (2 inch) hole with a plastic holder so it doesn't short out to earth like the ones with a metal bracket.

The sender unit has a 1/8" gas thread.

It has a built in dash light for night time illumination.