Ducted radial fan with forward-curved impeller blades, for direct installation in rectangular duct systems. Motor-impeller unit can be swiveled out. Housing made of galvanized sheet steel with standardized duct flange profiles on both sides, space-saving design, easy to service thanks to swiveling motor-impeller unit. Forward-curved drum impeller made of galvanized steel, good efficiency, low noise, aerodynamically optimized spiral housing, inflow via nozzle. Impeller-motor unit dynamically balanced. Drive: Maintenance-free single-phase AC external rotor motor, closed design, built-in thermal contacts wired in series with the winding (self-resetting), speed can be controlled using a 5-stage transformer or electronically (continuously), winding with moisture protection impregnation, sealed, low-noise ball bearings with long-term lubrication. Mains connection to pre-assembled terminal box (IP44).