The CDF540D RCD breaker manufactured by Hager is a 40A current limiting device designed for the protection of persons and property. It has an Inom rating of 40A, Ires rating of 30mA, and a maximum surge current of 250A. It operates at a voltage range of 240VAC. This device can be used to protect against electric shock from line-to-earth, line-to-neutral, and other possible fault conditions. Additionally, it works to protect the circuit from over-currents, when the current exceeds the value of the pre-set tripping current. It is an essential safety device to be installed in households, businesses, and power systems.