This was a life saver. My indoor cats suddenly decided they wanted to go outdoors (after a decade inside!) and would sneak outside every chance they got and then wanted back in 10 minutes later...and then back out. Back in. Out. Arrgh! Installed this and they were using it within 24 hours if not sooner (it's been a while since I installed it). Had to push them through a few times before they 'got it'. My large 15-20 lb cat and a 2 month old kitten both use it with ease. Highly recommend.

There was no hesitation with my cats, they went right through it. I like being able to lock it when it's cold outside.

2020 UPDATE: We still have this insert and it is a permanent fixture of our window. We now have a full screened in patio (with the pet/trampoline screen) for the cats to go in and out of and we also added two cats. Highly recommend this. We also added a door insert in our sliding door that goes out to the patio, but we have left this in so that the cats have multiple ways to get in and out of the patio in case one fails or just to keep the peace between them.

Wow, what a project it was installing this window sash cat door! But already it is worth it, and the cats love it. We used ours to put in our bedroom window which leads to a small "catio" that we built outside. We did not want to have to create any big holes in our doors or walls, so this Ideal Pets Sash - Chubby Kat is perfect.

Our cats are not fat, but they are tall, so we wanted to make it comfortable for them to get in and out of their catio. They learned very quickly how to use the cat door (same day) and did not want to leave their catio until we finally made them come in at 1 a.m.

We live in Florida, and it is so hot right now that we cannot supervise our cats in the back yard as often as we normally would - we have to wait for it to cool down. So this cat flap gives them the freedom to go outside and inside as they please, and it still keeps them safe from traffic and other potential dangers outside.

Anyway, back to the PROJECT of getting this installed. It took a lot of tweaking to finally get this to fit the way we wanted, especially to be able to make it as weatherproof as possible. Our window is about 35 inches wide. This window sash has springs on each side so that you can push the sides in to get the sash into your window frame, and then when you let it go they stretch back out and are tight in your window. The small silver knobs are basically just used to tighten that mechanism so that once the window sash is in place, you secure them and they will no longer be able to be moved. This sounds very simple, and for the most part, it was, but I am here to explain just a couple of things we had to do to get ours to work.

Although the sash fits width wise into the window frame and weather stripping is provided, we ended up using about 7 feet of our own weather stripping to secure this thing. It comes with black weather stripping, which would have looked terrible all around the window and sash. We had to line the bottom of our window, the bottom of the window frame (tracking), both sides of the sash, in between any holes that were exposed between the window and top of sash. Also, we had to weather strip the sash itself from left to right all along the front below the cat door flap and silver knobs, as well as much more behind the sash to fill in any spaces created near the bottom window tracking.

It takes a little bit of work to get the sides where you want them and to tighten the flexible side mechanisms just right as well as getting the sash at the height you want it. If you take a close look at the item you will see that the plastic cat door in the center has a white plastic frame around it. This will have to sit above your window tracking or else you will create a huge gap, letting air in and out, etc.

In short, just be prepared with your own weather stripping (I suggest white colored), and I mean many feet of it, in different widths and also in different thicknesses (yes we had to choose different widths and thicknesses for our weather stripping.)

It was a lot of careful and detailed work, but it really only took about 3 hours to complete - and that is definitely worth it for the amazing outcome! We are so happy with how this turned out and our cats are too.

A couple of other things to note: despite all the work on the weather proofing, the product itself has a few features that will make it unable to be perfectly fully weatherproofed. As other reviewers mentioned, this is a cat door. The swinging door is surrounded with gray bristles that act as its own little weather strip, but those definitely let some air in and out. I believe the door is magnetic so that it should close behind your cats automatically, but since they have to make that magnet weak enough for a cat to get in and out of the door, it doesn't always fully close. We have only noticed this a couple of times. For the most part. it does close all the way. Above the swinging cat door is also a little bit of space that is not weatherproof. These are just small considerations to be aware of.

In all, the small amount of air that may get in and out is probably much less than when you are opening and closing the doors to your house.

I hope this information helps. We love this product and our cats do too!

If this review helped you please feel free to select "helpful" and/or leave a comment.

I have a boxer mix who has discovered that she can fit through the fat cat version of this cat door. Unfortunately, I can't convince her that that is not good behavior. It wouldn't be a problem except that she can get in our house but not out when she is home alone, so I will have to order the version with a smaller opening.

The media could not be loaded. This cat door is fantastic! We rent, so we can't put in a permanent cat door. We were leaving the door open a little so the cats can go in and out, but after a $400 gas bill we decided to look into our options.

Location is everything... We decided to put the door in the bedroom because the window doesn't face the street, but the cats thought we were trying to kill them when we were introducing them to the door, so we moved it to a place more familiar to them. Once installed, we propped the door up so the cats could go in and out without worrying about the door. The cats were suspicious at first, but are getting the hang of it. The only issue is we have cats that guard the door and won't let the other cats pass, like the little jerks they are.

I did make a little glow in the dark pull tab from sculpey III because the door is stiff and it tends to get stuck swinging out, making it hard to align the door with the lock. I put a hole in it so I could attach a string to it so I can keep the door in the open position until they get comfortable with it.