The ES Non-programmable thermostats offers Best In Class 22 A Max Rating for larger heating circuits. Use where high accuracy is desired, and programmability is not needed. With a large back-lit display, this line voltage thermostat offers one of-a-kind in features including a memory backup for power outages. All the features you want with only two buttons. Simple has always been better. Two keys on the front control the temperature up and down. With comfort color back lighting and an on/off switch to control the illumination and system. Comfort color back light display is blue at 65 deg F and red at 75 deg F and varies in color between making it quick and easy to know your temperature. The illuminated LCD display can be read across the room making it easy to see at night. Simple, accurate control is the goal of the ES model. No fancy programming, just dependable temperature control for your home, saving money on your heating bills.