H2O Gauge

I think he has a thermocouple type gauge, not a capillary style tube type. So it’s just the probe copper looking end (the anode/cathode) being held in the coolant. I’ve ran a similar style device to turn on cooling fans automatically. I remember that I had the cathode/anode inserted In the upper radiator hose and the hose clamped down over it, sealing it over, with about an inch or so of anode/cathode hanging out in the coolant.