Extech 380801 True RMS Single Phase Power Analyzer/Appliance Tester Compact, battery operated appliance tester for analyzing AC power loads Four simultaneous displays of Watts, Power Factor or VA, voltage or Hz, Amps True RMS voltage and current measurements of sine, square, triangular and distorted wave forms with a crest factor &lt; 5 Plug device to be tested directly into the power analyzer Max, Data hold and overload protection