Patented Auto-Monitor Every 5 Seconds 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. Always Safe The GFCI features low power consumption and long service life. The surge protection and lightning protection function withstanding 6 kilovolt. Performed 6000+ times factory test, which is twice the testing times of UL standard.