Plug-in appliances, devices and gadgets that go into standby mode when not in active use still consume power and waste electricity and money. Some items continue to pull power from wall outlets even when turned off. The P3 Kill A Watt indicates how much power a device or appliance is consuming both on and off-duty. Just connect the power meter to a wall receptacle and then plug an appliance into the meter’s outlet. Take one reading with the appliance running, and another with it turned off. A surge protector version also is available to show the power usage of different devices.• Operating Voltage: 115 VAC • Max Voltage: 125 VAC, 50 / 60Hz • Max Current: 15A • Max Power: 1875 VA • Weight: 5 oz. • Dimensions: 5-1/8" H x 2-1/2" W x 1-1/2"