https://www.johnsoncontrols.com/building-automation-and-controls/hvac-controls/thermostats/submaster-high-volume-output-thermostat
The T-4003 Submaster Thermostat is a high volume proportional thermostat. The T-4003 can be reset from a remote location, or in accordance with a referenced...
high volumejohnson controlssubmasteroutputthermostat