Review on PetSafe Cat Door for Interior Doors - 2-Way or 4-Way Locking Flap - Enhancing Privacy for Cat Litter Box or Automatic Feeder - Sturdy Frame, Easy DIY Installation, Including Hardware Kit - Ideal for Pets Up to 15 lb (240 Oz) by Mike Wallace

My advice on this door is BUY WITH CARE. I chose this door because it is suitable for large cats and has good reviews. Although I accidentally didn't read the reviews. There are some problems with the door. 1. Comes with an installation template that fits on one side of the cat door but not the other. So when you insert the cat door main body into your door, it will fit perfectly, but the other side will not fit perfectly. I have no idea why they designed it that way, but it makes no sense and makes the whole process very frustrating. 2. This cat door is not designed for a hollow door. So if you install them on an interior door in most homes, you will have a hole between the two pieces. From what I've read in other reviews, people have had problems with their cat tails getting stuck in doors. To prevent this, we took another reviewer's advice and placed the foam in the middle. It looks gross, but at least there's no gap. Finally, the size of the door is decent. Our cat is 13 pounds and is very large and squishy. His tail tends to get stuck on the exit door, but that doesn't seem to bother him because it doesn't get stuck.