Dimensions: Pet door outer frame: 25cm x 31.5cm, inner frame: 21cm x 24.5cm. Suitable for small to medium sized pets. Sturdy and Durable: The frame is made of high-quality ABS material and equipped with reinforcing screws for easy installation. With a swivel design, be careful not to damage the swing door. Convenient for daily life: perfect for balcony doors, owners don’t have to open the door for pets often. A separate pet entrance and exit will not affect the normal use of the door after installation, and can also prevent mosquitoes and insects. Easy to use, there are magnets at the bottom of the door frame that close automatically; The element is light enough not to disturb your pets and it is easy to understand how to use it; There are locks on the left and right sides of the door to fully lock the door and Control your pet’s access. Recommended pet plugs are suitable for fly screen doors, windows and other screened areas; the inner plug does not include a grille, you need to install the cut-out grille inside the cat door frame.