Special order 1-week The V-Series fans are powered by an external rotor motor with a mixed-flow impeller. A mixed-flow impeller design is a cross between vane axial and centrifugal fans allowing for a higher static pressure (more air volume) than any other comparable impeller design of the same wheel diameter. Furthermore the V-Series fans operate between 1500 and 1700 RPM and the speed varies full-range, making them the quietest fans on the market. V-Series fans are available in 10 configurations. 3 year warranty. Specifications 12” to 16” duct diameters From 2050 to 4515 CFM Aerodynamic design allowing more air flow 100% speed controllable easing air flow adjustment High quality maintenance-free balanced motor, equipped with a mixed flow impeller, allowing an extremely quiet operation Extended collar and lip, allowing easy duct hook-up Permanently lubricated sealed bearings Prewired with 120V power cord 3 year warranty ETL Listed