Radial duct fan with 2 performance levels 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, built-in thermal contacts, sealed, low-noise ball bearings with long-term lubrication., Power control: by means of electronic controller or step transformer or two-stage operation with type DS 2/2 (accessory, item no.: 1267).