I bought this door expecting a great fit. Vertically it adjusts and fits fantastic......... the bad part is that rarely is any sliding glass door is perfectly square. Most screen doors contain a locking mechanism and other brackets that are typically used. I had to remove all hardware that normally enable the door to lock. My door was not perfectly square and the insert did not create a uniform seal. I had to spend an additional $20 on weather stripping and apply it to the inserts top and the side that rests against the frame of the door jam, more along the bottom once installed and additional to weather stripping was applied to the existing sliding door in order to create a complete seal. Additionally i had to cut a piece of wood that i could wedge in to press the sliding door against the dog door to get the seal between the two surfaces to be effective as the installation instructions were not clear and it appeared that permanent modification of the existing screen door would be required.

I needed a pet door to fit in a sliding patio door, and needed it quickly as I had just moved into a new home and couldn't be opening and closing doors for my cats many times a day. This did the job and was indeed easy to fit and install. My cats have learned to use it fairly quickly. The only thing I could want improved is the pet door itself, which is a bit flimsy and ill-fitting, and has no locking mechanism except to block the whole door with the insert provided. Ideally I'd have a door with a four-way locking mechanism, like the through-the-window pet door I had in my old house, but apparently the company that made that door no longer makes it.

Has definitely met the need. As others have said, it was quite easy to install, the instructions were clear and all the parts were in the box. The flap stays down, even in strong winds and the insert itself is narrow enough that there is still room for the XL sized humans to walk through the remainder of the opening (we have the x-sm insert for 10 lb dogs). I was unsure as to how tall the step would be for our small sized pups, but they are charging through the door w/out breaking stride, so no concerns there. The security flap insert is durable, but we did have to find another way to lock the door as this particular unit doesn't allow your door to lock into the insert, one of the reasons I didn't give 5 stars. I took one star off b/c there are significant gaps that remained between the door frame and insert even after using the weather stripping that was included. A quick trip to the local hardware store remedied that, although I've yet to go through a winter (sub zero temps) and can't speak to the efficiency of the weather strip/insert during that time of year. Our door is heavy vinyl, and although product is aluminum, it seems to work just fine. Would have liked larger variety of colors to choose from as our basic tan/taupe color is not available.

We weren't sure if Emma, our one year old Lab, would adapt to one of these doors. But then she squeezed through a cat door when we were visiting relatives. So I carefully measured our patio door opening and ordered one. Oops, it was about a half inch too big. But I was able to cut it down to size with a hacksaw in about ten minutes and replaced the lower panel with a thin board I painted white Looks pretty good. Our dog LOVES it! She pops in and out at will, goes out in the yard and gets a ball to bring in a drop in our lap when she wants to play. She is a bit of a tease and she used to come to the door to come in and then was away when we went to open the door. Very annoying, but no more.

I have a '70's Fox and Jacobs home with two sliding patio doors that are just slightly shorter than standard. Had to trim about 1/4" from the top of the pet door spring loaded sliding insert in order to get a proper fit, but after a quick modification with a Dremel Tool, a relatively easy and tight installation. I did purchase additional weather-stripping from the home center for the seam between the patio door and the insert and used the provided weather-stripping between the insert and the door frame. Training is not quite completed, two of my three cats are readily going in and out...Mom isn't quite there yet. I should have bought one of these years ago for my last two girls...