New Armor Flex pet doors are like no other pet doors on Earth. These ingenious new 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 and 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 dog and cat 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.