ClimateMaster ATA11U01, ATA22U01 Heat Cool/Heat Pump Thermostats are wall-mounted, low-voltage thermostats designed to maintain room temperature by controlling heating and cooling systems. They feature a large, easy-to-read LCD display and simple push-button controls. These thermostats are compatible with most heating and cooling systems, including heat pumps, furnaces, and air conditioners. They offer a variety of features to help you save energy and stay comfortable, including programmable settings, a built-in timer, and a vacation mode.