Siemens Speedfax™ B240H00S01 Molded Case Circuit Breaker With Insta-Wire, 120/240 VAC, 40 A, 22 kA Interrupt, 2 Poles

Circuit breakers provide a manual means of energizing and de-energizing a circuit. In addition, circuit breakers provide automatic over current protection of a circuit. A circuit breaker allows a circuit to be reactivated quickly after a short circuit or overload is cleared. Unlike fuses, which must be replaced when they open, a simple flip of the breaker's operating handle restores the circuit.