Housing easily removable for cleaning without tools. Pleasantly quiet. Dirt-free and quick replacement of existing EN and ET units, as 100 percent compatible with previous EN and ET units. For existing electrical external dampers with plug connection: disconnect plug and reconnect individual wires according to EN wiring diagram. Fan maintenance-free. Motor: Thermal overload protection as standard. Robust motor. Suitable for continuous operation. Electrical connection: Electrical "to be connected if protection against contact with impeller is ensured in accordance with DIN EN 294.