6inch 240CFM Metal Impeller Blade Duct Fan Booster Exhaust Vent Air Cooled Hydroponic Inline Blower Flange Size: 6" 240CFM. This 6" Duct Fan is in high quality, all steel construction. It is a Ideal choice for venting a growing area. Voltage: 110V / 60Hz. Heavy Duty Metal impeller blades.