The door didn't fit the heigth of my sliding glass door, although my measurement was within the parameters of the description. It was about 1/4" too tall to compress enough to fit. I had to take a saw and remove about that amount from the top. The other issue I have with this door is that when the wind blows the flap blows open even though the magnets should keep it in place. Since this is a temporary "fix" for me, I kept it and am dealing with it. I gave it 3 stars because it is easy to take in and out and my 100 lb Rottie does fit through the opening.

Pros: the door was easy for my husband to install. Its nice to not have the door open especially when it's raining or cold outside. It also keeps the flies outside during the summer since they can't fly straight into our house. The product is well made & looks great. We've had it for a few months now.
Cons: we couldn't install the door to fit flush with our sliding door. This is because of the size/configuration of our door tracks. It fits on the track for our screen door though which is ok. I purchased this with the intent of it fitting flush with the sliding door so it would provide a tight seal & prevent the cold air outside from getting in. It's still a huge improvement from leaving our back door open though and I would still highly recommend this product.
Side note: this is the first "dog door" our dogs are using so it took a few days or us pushing them back & forth with treats on the other side for them to get the hang of it but after 3 or 4 days they were running back & forth like pros!

I had to do a couple of modifications to get it to fit between my two sliding screens but it was worth the effort. Only part I do not approve is the stick on vinyl that covers the gap when door is slid up to pet door. It came in two pieces leaving a seam in the middle and the glue does not stick well.

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.