This is a circuit breaker that combines thermal and magnetic trip mechanisms to provide reliable overcurrent protection. It has a rating of 40 amperes (A) and supports both alternating current (AC) at 277 volts (V) and direct current (DC). The device features a lever operation, allowing for manual tripping in addition to automatic shutdown. It is designed for mounting on DIN rail, making it suitable for use in industrial or commercial applications where space-saving and efficient installation are required.