Ducted radial fan with backwards curved impeller blades, for direct installation in rectangular duct systems, fan unit can be swung out. Housing made of galvanized sheet steel with standardized duct flange profiles on both sides, space-saving design, easy to service thanks to the swing-out motor-impeller unit, from BG 450 additional locking of the swing-out unit. High-performance radial impeller with backwards curved blades made of plastic. Vibration-free operation thanks to dynamic balancing in accordance with quality level G 6.3 DIN ISO 1940 T.1. Drive: Maintenance-free single-phase AC external rotor motor, closed design, thermal contacts led out to terminal board, speed adjustable using 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 (IP54).