Whether you live and work in the Great Plains or North where the temperature plummets, or in the South or West where Summer is endless, the cost of energy has sky rocketed. So, either heating or cooling the back yard with old fashioned dog doors just won't do anymore. In some cases the energy waste is like opening and closing the door itself 4 or 5 times a day. Perfect Pet by Ideal has the answer with The All WeatherInsulated Dog Door's air pocket between 2 soft flaps, making it a great energy efficient insulator. We use energy efficient structural foam molded plastic, with interior and exterior locking panels for both flaps. Optional wall kit sold separately. Fit Tip: Be sure to choose the correct size Perfect Pet All Weather Series Insulated Dog Door for your pet, by selecting the flap size that will allow them to comfortably pass through the door, without bowing or scraping their backs.