Duct fan Specification: in line duct fan Model No. Duct Diameter Housing length MAX. CFM BLADE TYPE Weight /Unit DF**4 4/*9MM 6 *0CFM Polycarbonate **0g DF**6 6/**0MM 6 **0/**0CFM Polycarbonate **0g DF**8 8/**0MM 8 **0/**0CFM Polycarbonate ***0g Features: 1) Blade material is polycarbonate 2) Material is 0.5mm galvanized steel 3) Moter:AC **0V & **0V & **0V&**0V, *0Hz/*0Hz, thermally protected 4) With or without grounded power cord 5) Dual crimped ends install in either direction Benefits: 1)solve air delivery problems without major systerm rework or expense 2)can be installed at any angle, and as exhaust fans in houses, bathroom, attics, grow room, etc 3)engineered for maximum boost with minimum noise 4) a permanently lubricated motor provides quiet maintenance 5)with balanced polycarbonate blades, these are ideal for boosting supply air, return air, and venting Packing information: Duct Diameter Quantity/Carton Carton Dimension Gross Weight 4 inch *5pcs *5.5**3.5**6.5cm *3KG 6 inch 8pcs *4.5**2.5**7cm *0KG 8 inch 6pcs *4**3.5**1.5cm *1KG