The MadMan Cooland Level Detector is a stand-alone device that detects the presence of Coolant / Water

The CLD2 is a tiny, pre-wired microprocessor controlled electronic coolant level detector.
This cost effective device will warn you of low coolant levels way before overheating becomes a problem. It is suitable for petrol and diesel engines, or even your water tank !

The unit uses metal sensing probes (Self tapping screws) to detect the presense of coolant, has a slosh feature to prevent alarming when on uneaven terrain and can be silenced or shut off completely at the touch of a button.