Review on 🐱 Ideal Pet Products Sash Window Pet Door, Adjustable Width 33-38", Cat Flap, 6.25" x 6.25" Flap Size, White, (33SWDCF) by Amber White

My windows have a track that is smaller on the sides than below - see photo. The width on the sides is only 5/8 which means the cat flap will not fit. But I just removed the adjustable tips and used a vise to gently bend the fins inward. (You still need to remove them if you need to remove the bottom silver buttons, which I had to do). You will need to use needle nose pliers to hold the rods to loosen the screws. I unscrewed the first screw with a screwdriver, but I was afraid of tearing off the head, so I used a small head for the other three. Track and ready installation. Actually, I'm glad I had to do it. This made the cat door very durable. It doesn't vibrate at all - it's stuck there. You should change the theme like this from the start - it works with a lot more windows and doesn't hurt windows that don't need it. This is a really nice cat window. Very solid, looks great. The supplied foam sticks well to the window. If you look closely you can see some window locks in the finished image which I added for security - these double bolt locks with rubber inserts work great - search "Lion Locks Sliding Window".