When there is a leakage current in the circuit or load equipment or the ground neutral, the GFCI plug can break the circuit automatically! It converts one outlet to three ground fault protected outlets! It can be used both indoors, as well as outdoors, thanks to its durable and robust build quality. Perfect for use in a variety of electrical equipment, such as generators, cleaning machines, power tools (saws, drills, air compressors), lawn equipment, cutting machines, chargers and more! This GFCI includes an extremely well-made, contractor grade three-outlet plug along with a 12/3 SJTW 2 ft cord that all conforms to ETL listing requirements. It also comes with three grounded outlets, which are well spaced. The test and use feature lets you know when it's safe to use, providing a visual indicator light. Simply press the TEST button, the indicator light should be off; press the RESET button, if the light is on - it's safe for use. Rated for 20 A, this three-outlet GFCI is compatible with almost all electrical devices. Go Green and follow the instructions located on the products package for recycling (visit the GoGreen Power homepage for additional details).