The large LCD display of the P3 International Kill A Watt will display real-time voltage and line frequency, (Hz), from a power outlet, and can display wattage, amps and kilowatt-hours consumed by a connected electrical appliance, allowing you to forecast your energy costs for every appliance in your home or business. Simply connect an appliance to the Kill A Watt, and it will provide the hard data you need to assess how efficient it is, and whether or not it pays to upgrade to a more efficient electrical device.