UEB US Plug Socket with Energy Meter Watt Voltage Current Meter Monitor Hertz Power Analyzer Measures Various Parameters: power (W), energy (kWh), volts, amps, hertz, power factor and maximum power (W), time, days Safety: overload Protection Function, overload warning Convenient reading: with large clear LCD, easy reading Save Money: calculates electricity expenses, kWh is vital as this is what your electricity bills are based on, help you to reduce your energy cost Low Power Consumption: powered by 2 x 1.5V LR44 batteries, low power consumption