The smj inline rcd adapter circuit breaker protects against the risk of electrocution and is approved to the latest european standards double pole protected essential for use in high risk areas such as outdoors by ponds and when using pressure washers you should use an rcd whenever working with any electrical device when an imbalance is detected the smj rcd cuts power faster than a heartbeat it is designed to be installed in a cable run to provide portable and permanently fixed protection one en