Review on Interior Pet Door with Built-In Cat Door – Ideal for Small, Medium, & Large Cats – Fits Indoor Hollow Core or Solid Interior Doors – Concealed Kitty Litter Box Furniture – Cat Doors for Interior Doors by Erica Johnson

What a cool thing! I didn't like the look of "swing doors" or the thought of cutting a hole in the middle of the door, so I was glad I found this. Our cat, Nightmare, had no trouble understanding how to use it. Now his food and tray are out of sight and we love it (he does too)! We installed it a few weeks ago and have been very happy ever since. We love watching the Nightmare emerge from its "hole". If I have one "negative" comment, I think the portal could be a bit higher in the middle, but that doesn't seem to be an issue for Nightmare. This makes him arch his back to go underwater, but cats do it anyway, so that's probably more of a problem for me. Or maybe he's just a big cat. Installation was relatively easy and straightforward. I started the installation process by using a pencil to mark a light "x" on the bottom of the door roughly where the cut would be made before moving on to step 1. This ensured I was cutting the correct edge of the door. I followed the rest of the instructions exactly as written and the door was removed, cut out and replaced in under an hour. It could probably go a little quicker, but I like to take my time so I don't screw things up. One more thing. If you follow what I did and mark an "x" at the bottom of the door, open the door and mark the inside (usually not visible) side of the door, then remove the hinge pin as instructed. Before cutting, lay the door across on a work surface and the door will be correctly oriented for installing Part A. If the outside of the door is facing up for cutting, you will need to flip the door to complete the installation sequence. No big deal, just a step towards efficiency and avoiding multiple door openings. I would recommend it to anyone who has a cat in the house.