The MUB (A) fans have impellers with backward curved blades, manufactured from aluminium. The MUB 355-450 is equipped with external rotor motors. MUB 500-630 are driven by an IEC standard motor. The casing consists of a corrosion-resistant aluminum frame with fiberglass reinforced plastic / aluminium corners of PA6; highly shock resistant. The double skin panels are manufactured from galvanized steel with 20 mm mineral wool insulation. To avoid condensation the profile is provided with a separate chamber to fix screws. The Multibox fans are delivered for straight through airflow but can easily be rebuilt due to removable panels. This allows flexible ventilation solutions. The MUB (A) can also be used as extract- or supply air unit in air handling units. Installation in any mounting position is possible.