Power Monitor, P3 International Kill A Watt EZ

Cut your energy costs and find out what appliances are actually worth keeping plugged in. Simply connect these appliances to the Kill A Watt® EZ, and it will assess how efficient they really are. A large LCD display will count consumption by the Kilowatt-hour, the same as your local utility.  Shows the operating costs of your household appliances; • Accurate to within 0.2%
Large LCD Display calculates cost and forecasts by week, month, and year.  Built-in battery backup.  Displays eight critical units of measure.