Pet door specifically for screen doors, allowing cats and small dogs to come and go freely. - Type: Pet door - Size: 17cm (height) x 15cm (width) - Material: Plastic - Application: For cats and small dogs - Features: Screen door specific Thank you for viewing. I bought this for my dog, but it was too small, so I'm selling it because I bought a larger one. It was very useful. Installation was also easy. I will sell it to someone who needs it. By the way, for my 3.5kg Toy Poodle, it's not impossible to pass through, but it's a little difficult. I haven't installed it, but I have opened it to check how easy it is to pass through, so please understand that. Thank you very much.