Ideal Pet Products Window Sash Pet Doors 40" - 45" Large Cat Flap 7.5" x 10.5"

Works great! It was literally the only cat door I could find that fit anywhere in my house which didn't require I build a kitty staircase lol! Feels expensive but I think they know they corner the market so I guess it's just how much these things cost. It is very well built. I had one for a sliding door. I guess it just confuses me because the sliding door version was twice the size but half the price. But since my only other option was making something with plexiglass and a cheap basic cat door, I decided to shell out so I didn't have to spend the labor dealing with it.

It is very well made and looks great! I felt it was a bit expensive but worth it because our cats love being able to access the screened in porch to bird watch!