The specified device is a circuit breaker, designed to protect electrical circuits from overloads or short circuits. It features a magnetic and hydraulic delay mechanism, which provides a time lag between the occurrence of an overload and the actual tripping of the breaker. This allows for more effective protection against electrical faults while minimizing nuisance trips. The breaker has a rating of 50A at 480V AC or 150V DC and is typically mounted on a lever panel for easy operation and monitoring.