PORTABLE ELECTRIC SOCKET TESTER - - Advanced socket tester to quickly detect whether the socket cable connection is correct or not. Compact size, light weight and convenient to use. Voltage backlit LCD display for voltage testing. PLUG PLAY- -Designed with RCD or GFCI test button, One Click to know the working status of the leakage protection. Perfect for protecting your safety from the risk of electrocution. BRIGHT LED DISPLAY - - Light patterns are well labeled on the back of the unit itself. The red LED indicators can light up clearly even in strong sunlight and can also be used in the dark for you to read quickly. 6 LED LIGHT PATTERNS - - With 6 easy-to-read indicators to show the status of the Socket Easy to Judge: Correct, Open Ground, Open Neutral, Live or Neutral Reverse, Live or Ground Reverse, Live or Ground Reverse, Missing Ground. WIDE APPLICATION - Widely used for electrical maintenance testing , Tests of office sockets, power strips and wall sockets in schools, laboratories, factories and other social areas. DIY acceptance and safety checkYou will save a lot of time testing socket problems.