Installation went very fast, but it would help if the instructions made it clear which was the top as I put it in upside down and couldn't get the flap cover off. ;-)

love it but we had to call for help to figure out how to remove the bottom silver knobs so it would fit snuggly. Needs to be an easier way to remove them if needed

Perfect fit! No sliding glass door, so great option

Purchased this in sale. Nice alternative then having to cut a hole in an exterior door. If I ever decide to move, no damage done. Now my window was just shy of the required height so i had to remove the bottom pane. I was still able to secure it in place and added additional weather stripping. I built a ramp out of scrap plywood and used some cinder blocks that I had handy for exterior steps. I don't notice any external air coming through although I'm sure it's not air tight. Dogs are getting the hang of it in just a couple days. Time will tell.

Fit the window perfectly and my kitty loves it! Picked up on using it right away.

This size fit into my window well. You will need extra insulation on the gap on top of the window since it stays open. One younger cat learned pretty quickly how to push open the flap. The older cat has not gotten used to it yet, still working with her on how to go out and back in.