The Portable GFCI units (Ground Fault Circuit Interrupters) offer protection for 2-wire or 3-wire appliances and tools to avoid electric shock for people in all work 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. They are perfect for indoor or outdoor use in a variety of temporary power applications, such as portable pools and generators, power pressure washer, submersible pumps, vending machines, dishwashers, drinking water coolers and bottle fill stations, 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.