"Rugged design provides continuous operation in workshops, barns, poultry houses, greenhouses, garages, anywhere air movement controls condensation and reduces stagnant air. 16in. fan delivers 2,600 CFM @ 1,650 RPM. HP 1/4, Fan Diameter in. 16, Air Delivery CFM 2,600, Speeds qty. 1, Dimensions L x W x H in. 21 x 13 x 23, Volts 115, Needs to be Hardwired Yes, Speed RPM 1,650. Totally enclosed air over TEAO thermally protected motor Heavy-gauge galvanized steel fan frame reduces rust and corrosion Built-in shutter opens automatically when fan is turned on and closes when fan is turned off Spiral guard has a polyester powder-coat finish and meets OSHA requirements Built-in shutter with rigid blades for long-lasting, continuous operation Must be hardwired"