Let your furry friend come and go as it pleases with the Perfect Pet Medium Pet Door. It features a reinforced design with a magnetic floating sill for secure closure. The Medium Pet Door has a tamper-proof mounting system and a molded ABS lock-out slide to restrict the pet's movements when necessary. It's easy to install and has a patented edge made not to warp and a flexible see-through transparent poly vinyl flap. The telescoping frame adjusts to door thickness from 1.25" to 2" and includes a lifetime warranty. This easy to install pet door is perfect for both Cats and Dogs!