?Energy-Efficient Ventilation?This powerful inline duct fan speed of 4500 RPM can create the air flow of 130 CFM, Maximum power consumption is only 6W. Upgrade DC motor & low noise effectively circulating air, quickly move vast amount of air to exhaust odors. ?Application Scenarios?The 4 inch booster duct fan designed to quietly ventilate grow rooms, bathrooms, kitchens, workshops, basements, attics and etc, in order to boost airflow in HVAC systems. ?Easy to Install?Hon&Guan air exhaust fan's blade and the body are made of high quality plastic, for quick removal and easy maintenance. ?Adjustable Controller? The 4-inch duct fan includes a variable speed controller, which can allows you to adjust the airflow and noise at will. ?Excellent Performance?Duct size: 4” | Dimensions: 7.28 x 3.82 x 3.82 in. | Voltage: 100-240V| Air Presssure: 165 Pa| Noise: 26 dBA