Whether your home has just been built or is an older home, it will likely have at least one room that usually lacks sufficient ventilation and either too hot or too cool. That's a result of bad airflow. Airflow in central air homes weakens the further it travels through the multiple bends of the ducts. Cyclone's Booster Fan Plus helps solve that problem by boosting the idle air from the vents outward into the rooms where it is needed, making every room in the home equally comfortable. The innovative design features a built-in thermostat that senses heated or cooled air and turns the fan on and off automatically, lowering your heating and cooling costs. The too-hot or too-cold room proves that it's happening to you. The Cyclone Booster Fan Plus helps SAVE ENERGY and MONEY. Just set it and forget it. The booster fans come as a pack of 2.