The High Tech Pet E Armor Flex Patio Door Medium Opening Tall Height is like no other pet door on Earth. These ingenious double-glass, Low-E Armor Flex patio pet doors feature a revolutionary, patent-pending flap design that creates an airtight seal, providing the highest level of extreme weather resistance and energy efficiency. The innovative new flap design is made of individual, interlocking segments, each precisely positioned by rare earth magnets. The interlocking segments pivot relative to one another to provide the horizontal rigidity required to create an airtight seal while providing vertical flexibility, making it easy and safe for your pet to use. These extremely high-quality pet doors are designed to be the best made cat and doggie doors on the planet, featuring heavy-duty aluminum frame construction, high-strength ABS composite flap construction and all stainless-steel hardware. The doors are finished with the toughest industrial powder coat to look beautiful and work perfectly for years and years. Compared to the next best pet doors on the market, new Armor Flex pet doors for patio access represent a big step forward in quality, innovation and technology with lower pricing to give you, not just the best pet door but, the best VALUE anywhere.