The smart socket tester is mainly used for polarity detection of power socket wiring and safety detection of leakage switch. The voltage and frequency of the socket can be detected to check if the wiring is correct or not. The tested result will display on the LCD screen clearly and you can press the storage button to save the current data.    Features:  Compact size and light weight, portable to use and carry. Plug and play, easy to use.  Fine workmanship ensures reliable performance and accuracy results.  Advanced socket tester for polarity detection of power socket wiring and safety detection of leakage switch to ensure electricity safety.  With the function of RCD leakage switch, you just need to plug the tester into a receptacle whose wiring is correct, and short press the RCD button. In this case the RCD switch should trip. Otherwise, the RCD is not working properly.  Storage, RCD leakage indicator, low power indicator, NEU-LIVE voltage indicator, test result indicator and NEU-GRD voltage can display on the LCD screen, and the indicator light will be on according to corresponding results.  Suitable for testing power sockets in houses, offices, schools, laboratories, factories and other places.    Specifications:  Model: FY1881-EU / FY1881-US / FY1881-UK (Optional)  Material: ABS  Color: Black  Power Supply: 2 * 3V CR2032 battery (NOT included)  EU / UK:  Testing Voltage Range: 30V~250V / 50~60Hz  N-E Voltage: 0.1V~10V  RCD Current: >30mA  RCD Working Voltage: 220V±22V  US:  Testing Voltage Range: 30V~120V / 50~60Hz  N-E Voltage: 0.1V~10V  RCD Current: >5mA  RCD Working Voltage: 110V±22V  Working Environment: 0°C~+40°C, 20%~75%RH  Storage Environment: -10°C~+50°C, 20%~80%RH  Item Size: Approx.   EU: 82*65*80mm / 3.23*2.56*3.15in  US: 82*65*70mm / 3.23*2.56*2.76in  UK: 82*65*72mm / 3.23*2.56*2.83in  Package Size: Approx. 9*8.5*7cm / 3.54*3.35*2.76in  Package Weight: Approx. 129g / 4.55oz    Packing List:  1 * Socket Tester  1 * User Manual (English)