PRICES MAY VARY. Quiet Register Booster Fan: A quiet fan system designed for improving wall and floor vents airflow from HVAC systems to increase home comfort. Eliminate Uneven Room Temperatures: Biowind smart register vent equipped with programmable LED controller and high-precision temp sensor to work with HVAC. It can automatically turn on/off vent fan to heat or cool the rooms at the right time. New Upgraded Remote Control: Remotely adjust the fan speed(0-10 level）to meet user different needs and make a perfect balance between noise and comfort. No need to get up, More convenient. Energy-Saving & Cost-Effective: This vent booster fans are more energy-efficient to traditional AC and cooling devices. They rely on airflow to improve indoor temperature and circulation, maximize the heating