SO easy to install, such a good product!
Cut a huge hole in my door????? Sounds like a very difficult chore. NOPE, it really was pretty easy, and took very little time. This is a well made, well-designed door. I got the training flap, and followed the directions to teach my tiny, skittish dog to go thru. It took about 10 minutes (we took a break). I could not be happier with it.