Simply plug it into a powered mains socket and then plug your appliance into it. The meter will monitor the energy usage of your appliance.The Energy Saving Power Meter will measure the energy use (and calculate costs) of running household appliances.This helps you lower your power bill and reduce carbon emissions, as you discover which appliances are the worst energy offenders and then work out ways to limit their use. You can plug any 13 amp-rated household appliance into this power meter in plug adapter format to access its energy consumption and carbon footprint. Technical details Week day indication Yes Clock function Yes Displayed energy consumption units kWh Audible alarm(s) Yes AC outlet types Type G (BS 1363) AC outlets quantity 1 AC outlet(s) Display Built-in display Yes Power Maximum current 13 A Maximum power 3120 W Power source type AC, Battery Battery Battery voltage 1.5 V Battery type AG13/LR44 Number of batteries supported 2 Weight & dimensions Weight 200 g Operational