Review on AETAPETi Cat Door: The Perfect Solution for Interior and Exterior Doors, Sliding Screens, Glass Windows, and Door Flap Access for Your Feline Friends by Julie Spalding

Excellent value for money installed on 3 hollow interior doors. The locks are a little tight, but that's not a problem. There was one instance where my cat accidentally locked it but they started attacking each other as they walked by. The fact that this has only happened once makes me happy that the locks are a bit tight. I recommend enlarging the section a bit. I made mine as small as possible and they worked fine until I put the doors back on their hinges, at which point two of them started struggling to open. Since these are interior doors, I simply removed the insulating strips and the problem was solved. Definitely recommend.