1---Size: pet door outer frame: 25 cm x 31.5 cm, inner frame: 21 cm x 24.5 cm. Suitable for small and medium sized pets. 2---Sturdy and durable: the frame is made of high-quality ABS material and attached with reinforced screws for easy installation. With a swivel design, it is careful not to damage the swing door. 3---Easy for daily life: Ideal for balcony doors, owners do not have to constantly open the door for their pets. A separate entrance / exit for pets does not affect the normal use of the door after installation and also serves as mosquito and insect protection. 4---Easy to use: There are magnets on the bottom of the door frame to close it automatically; the element is light enough to not disturb your pet, and it is easy to understand how to use it; there are locks on the left and right side of the door to fully lock the door and control the access of your pet. 5---Recommendation: The pet stopper is suitable for fly screen doors, windows and other shielded areas; the inner stopper does not include the grille, you need to install the cut out grille inside the frame of the cat door. Features: Material: ABS Product size: 25*31.5*1cm Colour: black, white Weight: 360g