About this item Tester outlet adopts RCD/GFCI test button design, one-click understanding of leakage protector working status, effectively preventing electric shockSocket Tester is widely used in electrical maintenance test, desktop socket test, standard test and wall socket test in schools, laboratories, factories and other social areasRCD Plug-tester is made of ABS plastic, which is strong and wear-resistant, resistant to rust and corrosion, and can be used for a long time Output detector in plastic comes with 6 easy-to-read indicators to indicate the status of the socket, which is easy to judge The LCD display of the automatic voltage Polarity Detector electric circuit can test the voltage, which allows to quickly check if the plug wire is correctly connected