Does not requires scraping of ice surface it is done by the window heater for you effective 12v additional window defogger is effective even with strong minus temperaturescan be easily turned off and on easy to store light weight high functionality for protecting the vehicles battery we recommend using a 12v power station or a 12v time switch in order to have the windows of your vehicle free on the right time before departure can also be used as heater for sleeping back together with a