Cyclone Booster Fan for Sale. Helps solves poor airflow from ductwork. We purchased three units for your home (with great results), but only needed two, so we're selling the spare unit for $35. It has never been used, but the box has been opened. Below in info from the manufacture ... Cyclone Booster Fan assists and maximizes the airflow from central heating system to pull the air back into your rooms. Designed to maximize the airflow from central air units (ie: warm-air furnaces & AC), it pulls air back into the room so the environment stays at the comfort level you want. The built-in thermostat activates at the set temperature ensuring consistency, while the angled blades push air deep into the room. The fan is designed for quiet efficiency all year round. * Built-in thermostat automatically turns fan on at the set temperature * Fan is quiet and efficient, and effective all year * Fan blades are angled at 45 degrees to push airflow into the center of the room * Fits in both a 3" x 10" and 4" x 10" register slot For more info, please go to https://www.homedepot.ca/en/home/p.booster-fan-plus-in-white-with-built-in-thermostat.1000486274.html