Industrial Fan Guard Fan Accessory Type Industrial Fan Guard Guard Dia 21 in Fits Fan Dia 18 in For Use With 48 in Frame Motors 56 in Frame Motors Mounting Slot O.C. A 2 3/4 in Mounting Slot O.C. B 4 1/2 in Material Steel Color Gray Fan Accessory Finish Polyester Powder Coated Includes (1) Front and (1) Rear Section Standards cULus Listed OSHA compliant wire guards