The 4 Stage Cooling Thermostat is an innovative product designed to automatically adjust the temperature of a room so it remains comfortable and energy efficient at all times. It works by monitoring the temperature in the room, then activating the cooling or heating components when needed. The four stages refer to the different settings that can be programmed into the thermostat. These include day-time, night-time, vacation mode and away mode. The day-time setting will keep the temperatures at your desired levels during the day while night-time mode will decrease the temperatures slightly at night. Vacation mode will maintain a lower temperature when you are away and away mode will shut off power completely when nobody is present, saving energy and money.