FeaturesKit Includes: Wireless FocusPRO#171; Thermostat Powered by RedLINK reliability No interference with other wireless devices in the home Installs in minutes Displays outdoor temperature and humidity (outdoor sensor sold separately) 1 year battery life 2 month low battery warning Equipment Interface Module (EIM) All HVAC equipment is wired to the module Module receives communication from all wireless devices Return Air Sensor Works with the EIM to maintain safe indoor temperatures if power is lost at the wireless thermostat Same great features of the FocusPRO#171; thermostat now wireless Choose from programmable or nonprogrammable kits