Question about PetSafe Petporte Smart Flap

Hello, I ordered a "Staywell cat door 200" for my Maine Coon. Unfortunately, the product is not optimal because the cold air gets into the house. I wanted to buy a more expensive cat door to solve the problem. The following: I have now had a hole made in the window with a diameter of 263 mm for the above-mentioned door. I can no longer find a suitable door. How wide is the Staywell Petporte Smart Flap? Is there a round glass adapter for it? Does anyone have a recommendation for my problem? Thank you