Module receives communication from the wireless devices.
Powered by RedLINK reliability. Honeywell YTH6320R1001 Wireless FocusPRO Programmable Thermostat Grey EQUIPMENT INTERFACE MODULE(EIM): All HVAC equipment is wired to the module. Return Air Sensor Works with the EIM to maintain safe indoor temperatures if power is lost at the wireless thermostat. RETURN AIR SENSOR: Works with the Equipment Interface Module to maintain safe indoor temperatures if power is lost at the wireless thermostat.