The Hager CEA440D is a four-pole residual current circuit breaker designed for electrical safety applications in industrial and commercial environments. This type A residual current device offers a rated current of 40 A, a fault current of 0.1 A, and a rated voltage of 400 V for reliable protection against earth fault currents. The multicolored design indicates different phases and neutral connections, allowing for clear identification during installation and maintenance. Its compact design integrates overload and fault current protection functions into a single unit and complies with European electrical safety standards. Suitable for fixed installation in distribution cabinets, the device provides high tripping capacity and durable mechanical components for long-term reliability. The CEA440D model is the successor to previous Hager circuit breakers, combining improved tripping characteristics with enhanced thermal stability. Installation requires qualified electrical expertise and adherence to local installation regulations. The unit is supplied as a single device, ready for mounting on standardized DIN rails in electrical cabinets. Hager's engineering focus on precision and safety makes this circuit breaker suitable for protecting circuits with electronic devices, where type A sensitivity is necessary for detecting alternating and pulsating direct fault currents. The robust housing materials ensure consistent performance under temperature fluctuations typically encountered in electrical distribution environments.