Prevent shocks from extension cords connected to boats, RVs, and other large electrical systems. These ELCI (equipment leakage circuit interrupters) converters monitor the flow of current to and from an electrical system. If they detect an imbalance, they cut off the power. They’re similar to GFCI converters, but they monitor an entire system rather than one device. They also tolerate a higher level of imbalance before they trip. These converters have a manual reset to keep equipment from starting unexpectedly.