Radial duct fan for direct installation in the duct system. For conveying medium and small air volumes against high resistance., Housing made of galvanized sheet steel with round connection pieces adapted to standard ducts., Radial impeller with backwards curved blades made of plastic. Pressed directly onto the motor and dynamically balanced as a unit. Low noise, high efficiency., Single-phase AC external rotor motor, closed design, maintenance-free, speed can be controlled by reducing the voltage, built-in thermal contacts, sealed, low-noise ball bearings with long-term lubrication.