The HE1035B Heater and Thermostat assembly are used in the old style Brower Automatic Waterer MK units. The set comes complete with the thermostat and coil heater already wired. The thermostat senses the airspace and will turn the heater on around 40 degrees and shut off at around 60 degrees.
The thermostat and heater is not designed for water submersion but should be installed as a replacement for the existing thermostat.