Two-stage fan unit. Two swiveling MV fans connected in series are connected using a sleeve and mounted on a common base plate. Supplied as a ready-to-assemble kit. The pressure output is roughly doubled by series operation. Housing made of impact- and corrosion-resistant plastic, light gray in color, with molded mounting bracket for easy installation on the wall or ceiling and intake and exhaust nozzles corresponding to the standard pipe diameters. By loosening the clamps, the fan unit with terminal box can be rotated into any position and removed for maintenance and cleaning. Supplied including dowels and screws. Semi-axial impeller, eight spatially curved blades made of thermoplastic. Vibration-free operation thanks to dynamic balancing in accordance with quality level G 6.3 VDI 2060 and DIN ISO 1940. Closed, ball-bearing capacitor motor with moisture protection, insulation class F, for continuous operation. Maintenance-free and free from radio interference. Motor protection through thermal overload protection in the winding.