The ESRTD3 is an economical and simple to use Digital Room Thermostat. Simply turn the control dial to the desired temperature to control the room temperature. The ESRTD3 includes a LCD display powered by an internal rechargeable battery. The LCD display shows the current room temperature. When the temperature is adjusted, the LCD display will briefly show the revised temperature before returning to the current room temperature. A small flame symbol will appear on the LCD display when the system is calling for heat. The TPI & Delayed Start option provides further potential energy savings, with the opportunity to save up to 10% on heating costs. Large, clear adjustable dial TPI technology Delayed start LCD display Temperature control accuracy of +/-0.6°C, Manufacturer: ESI Controls