Medium-pressure tube fan with cylindrical tube sleeve, flanges on both sides, directly driven. Cylindrical tube made of galvanized sheet steel, with flange molded on both sides, hole pattern in accordance with DIN 24155 sheet 3 with integrated guide vane. Axial impeller made of plastic with 14 spatially curved blades. Vibration-free operation due to dynamic balancing in accordance with quality level G 6.3 VDI 2060 and DIN ISO 1940. Three-phase squirrel-cage motor, speed controllable by reducing the voltage, thermal contacts, closed design, maintenance-free, sealed, low-noise ball bearings with long-term lubrication.