Check the listing for details. VIVOSUN Inline Duct Fan 4" 190CFM AC Variable Speed Controller HVAC Exhaust Blow. Color: Black, Condition: New. Listed at 49.49 USD. About this item Energy-Efficient Ventilation: This powerful blower with a fan speed of 2300 RPM can create an air flow of 190 CFM; It combines the features and benefits of axial and centrifugal fan, effectively circulating air Low Noise Level: The durable fan blades revolve smoothly and powerfully, which helps collect airflow volume and cut noise output; A less than 30 dB noise level will not disturb your work Adjustable Speed: A stepless speed controller on the power cord enables the fan to run at different speeds; With this speed switch, you can adjust it to the desired airflow level Easy Installation: This duct fan is compact and lightweight so it can be installed in small areas; Comes with an installation bracket indicating the direction of the airflow; Removable duct ends with locking tabs Versatile Applications: Suitable for industrial, household and horticulture ventilation applications; It can quietly and efficiently moving large volumes of air throughout your ventilation system Specification： Diameter: 4 inch Power Supply: 110/120 V Power: 59 W Current: 0.8 A Speed: 2300 RPM Air Flow: 190 CFM Noise Level