This large pet door mounts into an interior or exterior door, letting pets come and go on their own instead of you opening the door every time. The 10 1/4 x 16 1/4 inch flap is built with a full metal frame and double magnetic closure, so it sits flush against the frame and helps block wind, rain, dust, and small unwanted visitors from slipping in. It fits doors between 1 1/16 and 2 inches thick, covering most interior and exterior doors, garden doors, and similar walls. The flap opens smoothly with light pressure so pets can pass through without hesitation, and all mounting hardware is included for a straightforward install in just a few minutes. At 9.9 pounds, the complete metal-framed unit is solid enough to handle years of daily in-and-out traffic without loosening at the hinges.