Check the listing for details. VIVOSUN 4"/6"/8" Inline Fan HVAC Exhaust Blower Ventilation Fan 100/240/420 CFM. Condition: New. Listed at 23.74 USD. About 4"/6'/8" Inline Fan Durable: The fan has a strong motor which features a permanently lubricated bearing that operates quietly and requires no maintenance Compact But Efficient: This duct fan is compact and lightweight enough to be installed in areas with little available space; With a diameter of 4 inches, speed of 2930 RPM and 100 CFM air flow ;With a diameter of 6 inches, speed of 2960 RPM and 240 CFM air flow;With a diameter of 8 inches, speed of 2970 RPM and 420 CFM air flow Low Noise: Superior balanced centrifugal impeller for long service life & quiet operation; 30db 37db 40 dB noise level does not have any harm and will not disturb your work Wide Applications: You can have it in bathrooms, kitchens, workshops, basements, attics and etc, in order to boost airflow in HVAC systems; Also, it can be used in grow rooms as intake fans or exhaust fan Specifications: Voltage 110/120V, Power 40W; Max Operating Temp of Motor is 130℃ / 266℉; Max Ambient Temp is 60℃ / 140℉; Note: Please turn the fan off immediately if the blades get stuck by other objects