"The Wallmaster exhaust fan eliminates heat build up in barns, greenhouses and industrial buildings. Constructed with a sturdy 18-g. galvanized steel housing, a 1ft. x 2in. mesh intake guard and an exhaust shutter. U.S.A. HP 1/2, Amps 7.0/3.5, Speeds qty. 1, Speed RPM 825, Dimensions L x W x H in. 40 x 23 x 40, Volts 115/230, Fan Diameter in. 36, Air Delivery CFM 10,100, Needs to be Hardwired Yes. 4 wing galvanized steel blade Single-phase motor Guard is hot dip galvanized after welding and attached with noise-reducing clip Aluminum shutter has two tie bars to reduce flapping in high wind Maintenance-free motor"