By installing this Siemens® circuit breaker and surge protective device in the load center of your residence, protection is provided to all branch circuits. This product comes equipped with two green LED indicator lights. The circuit breaker and SPD use Siemens-built 150V. The maximum impulse rating for the SPD module is 40kA. The standard interrupting rating for the circuit breaker is 10k AIC (Kilo Ampere Interrupting Capacity). The devices are rated for 120/240V AC and calibrated for 40 °C maximum ambient applications.