Review on Purrfect Portal XL Pet Cat Door: Easy Installation in Minutes for Large Cats (Up to 30 lbs) on Interior Doors - Secure Entryway with Molded Plastic Pass - Includes Instructions & Hardware, White by Daniel Teller

My dad put this on our laundry room door because our dog ate cat poop. Disgusting I know. The bad news was that he would continue to eat cat food and leave the litter in the food bowl. In any case, this large size is quite large. It's wider than it is tall. The main reason I got the large size is because we had fat cats and older cats that didn't bend as well. And we figured it wouldn't be the last time we'd have cats that fit those descriptions, so a big door would be better for us. I will say one thing: if you have a door with decorations on the fronts, the shape or hole will leave gaps between them. See my photos for reference. The best suggestion I can give is to fill it with sealant that matches the color of your door. Luckily ours is white and I'll do that later so you can't see the cut side of the door at an angle. Otherwise we have shown it to our cats once and they use it with no problem. They're not afraid of him at all, and there's no barrier to stop them, so just walk through it.