Large, clear, backlit display is easy to read - even in the dark Displays room temperature, temperature setting, and optional outdoor temperature Front battery door access for fast, easy replacement Air filter, humidifier, dehumidifier, and HVAC service indicators Auto backlight (activated with first button press) Give your old-school heating and cooling system a higher education. The simple addition of a programmable thermostat allows you to create personalized programs based on your lifestyle, enabling you to heat or cool your home when you need it and reduce ene