The? wireless energy monitor updates every 6 seconds so you can instantly see the impact of turning a light on or off, boiling the kettle or using your tumble dryer. It has an innovative memory function that allows you to see how much you have used today, yesterday and in the last week or month. The? monitor also displays your daily average so you can see when you are using more electricity than normal and see how your average usage reduces as you change the way you do things.