Tubeaxial Fan Drive Type Belt Drive Includes Drive Package Yes Includes Motor Yes Blade Diameter 21 in Nameplate Voltage 115/208-230V AC Phase 1 Motor Horsepower 1/3 hp Airflow @ 0.000 in SP 3 522 cfm Maximum Noise Level @ 5 Feet 18.4 sones Assembly Unassembled For Air Type Flammable Vapor Blade Material Aluminum Housing Material Steel Number of Blades 6 Number of Speeds 1 Motor Enclosure Totally Enclosed Fan Cooled Standards AMCA Bolt Circle Diameter 22 1/2 in