Livingstone RCD residual current device, or safety switch, protects you from the most frequent cause of electrocution - a shock from electricity passing through the body to the earth. It can also provide some protection against electrical fires. RCDs are electrical safety devices designed to immediately switch off the supply of electricity when electricity leaking to earth is detected at harmful levels. They offer high levels of personal protection from electric shock. Injuries and fatalities can be prevented by the use of properly installed and maintained Livingstone residual current devices. A must for home and workplace safety.