This medium pet door pairs a sturdy aluminum alloy frame with a frosted PVC flap that's built to handle wind, rain, and cold without cracking. The flap opening measures 8.25 x 12.25 inches within an 11.30 x 16.02 inch frame, fitting doors between 1.06 and 2 inches thick, and it ships with a full hardware kit and installation guide so first-timers can get it done quickly. A hinge design on the flap makes opening and closing effortless for pets, while the magnetic closure keeps the seal tight and quiet against drafts and noise. A built-in locking mechanism and metal plate add extra security when you want to keep other animals out, and at just 4.7 pounds, the whole unit mounts cleanly onto interior or exterior doors without weighing the door down.