KAIWEETS KM117B is an electrical receptacle tester that tests the wiring conditions at an electrical outlet and inspects GFCI devices. The LCD displays the Phase voltage, Leakage voltage and Current, identifies SIX common wiring problems, correct, open ground, open neutral, hot/ground reverse, hot/neutral reverse, hot/ground reverse&open ground. It is designated for use with North American 3-wire 120V electrical outlets.