4 Inch Exhaust Fan Adjustable Speed Duct Fan Garden Farmland Window Airflow Boost Air Ventilator Pipe Ventilation Extractor ,Easy to Use

Energy Saving: Built with cutting edge brushless electronically commutated Motor (EC) motor and dual jet type impeller, our new ECMF series fans deliver 350 Cubic Feet per Minute (CFM) of Airflow using only 18 Watts Quiet &SpeedadjustableUsingincludedspeed controller ECMF series fans' speed can be adjusted from 0%-100% without creating any additional hum or background noise