Radial EC duct fan with backward 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. High-performance radial impeller with backward curved blades made of plastic and galvanized steel. Vibration-free operation thanks to dynamic balancing. Aerodynamically optimized, inflow via nozzle. Driven by energy-saving, speed-controlled EC external rotor motor with protection class IP44 with maximum efficiency. Maintenance-free and free from radio interference, ball bearings. Integrated electronic temperature monitoring for EC motor and electronics. Stepless speed control with potentiometer or stepless speed control with universal control system EUR-EC. Connection via standard terminal box (IP54) mounted on an extended cable.