4'' Silent Duct Fan Air Extractor Exhaust Ventilation Bathroom Kitchen Ventilator Wall Blower Industrial Fan ,Energy-Efficient

Fluted on both ends to receive ducting Balanced metal blades are for boosting air supply and venting exhaust air Engineered for maximum boost with minimum noise Household applications: help to boost airflow in HVAC units to remove exhausts and odors from bathrooms and workshops and ventilate basements and attics, etc. Grow room applications: used as intake fan to bring fresh air into grow rooms.