Two-stage fan unit. Two pivoting, series-connected MV fans are connected via a sleeve and mounted on a common base plate. Delivered as a ready-to-assemble kit. Continuous operation approximately doubles the pressure performance. Housing made of impact- and corrosion-resistant plastic, light gray in color, with an integrated mounting console for easy installation on walls or ceilings, as well as intake and exhaust nozzles corresponding to standard pipe diameters. By loosening the clamping brackets, the fan unit with junction box can be rotated into any position and removed for maintenance and cleaning. Delivery includes dowels and screws. Semi-axial impeller, eight spatially curved blades made of thermoplastic. Vibration-free operation achieved through dynamic balancing according to quality level G 6.3 VDI 2060 and DIN ISO 1940. Closed, ball-bearing condenser motor with moisture protection, insulation class F, for continuous operation. Maintenance-free and interference-free. Motor protection through thermal overload protection in the winding.