The Portable GFCI units (Ground Fault Circuit Interrupters) offer protection for 2 wire or 3 wire appliances and tools to avoid electric shock to users in all working environments. This GFCI outlet will automatically conducts a self-test (auto-monitor) every 5 seconds to ensure the GFCI is continually working to protect people from electrocution, which exceeds the UL standards of self-test frequency of 3 hours.Perfect for indoor or outdoor using in a variety of temporary power applications, such as generators, cleaning machine, power tools (saws, drills, air compressors), lawn equipment, cutting machine, vacuum cleaner, pumps, heaters, household electrical appliances,dishwashers,cord-and-plug-connected high-pressure spray washing machines,tire inflation machines and more. They are easy to install with providing 3 different grommets for wiring cable 14 AWG, 16 AWG and 18 AWG. Material: PVC.