4" Booster In-Line Duct fans increase the airflow in hard-to-ventilate rooms and settings. These are durable, quiet, and have simple installation. These fans can easily fit into metal or flex ducts. Its properties like strong motors, excellent performance, and higher temperature ratings set these booster fans apart. 

Each fan is highly rated for both heated and cool air and is perfect for outdoor and indoor usage. So, you can use the fan for multiple purposes. If you are looking for a durable, quiet operation, easy-to-install duct fan to fit into metal or flex ducts, this booster fan is the right choice. It serves the purpose of an exhaust fan to ensure proper ventilation.