Downblast Ventilator, Drive Type - Roof Ventilators Belt Drive, Drive Package With Motor Included No, Duty Rating - Roof Ventilators Standard, Mounting Location - Roof Ventilators Roof, Base Square Size - Roof Ventilators 46 In. x 46 In., Wheel Dia. 36 In., Number of Speeds 1, CFM Range 8693 to 18,322 @ 0.0 In. SP, Motor HP Range 1/2 to 5, RPM Range 325 to 685, Base Height 1-3/4 In., Overall Dia. 58-3/4 In., Overall Height 38-1/2 In., Shaft Dia. Wheel End 1-1/4 In.