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. 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: gt;30mA RCD Working Voltage: 220V22V US: Testing Voltage Range: 30V~120V / 50~60Hz N-E Voltage: 0.1V~10V RCD Current: gt;5mA RCD Working Voltage: 110V22V Working Environment: 0C~ #43;40C, 20%~75%RH Storage Environment: -10C~ #43;50C, 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)