PetSafe Dog Door for Screen Door – Size Large – for Dogs and Cats up to 100 lb – Use in Screen Doors – Window Screens and Porch ScreensENCOURAGE EXERCISE AND INDEPENDENCE: Give your cats and dogs freedom to go in or out without asking for your help to open the doorperfect for potty breaks or play time QUICK, DIY INSTALL: Snaps directly into your existing screen door, window or porch screen for easy installation, and blends perfectly with your existing screen DURABLE DESIGN: High impact plastic frame surrounds a strong mesh that is puncture and tear resistant for long lasting use;