A catio isn't just a structure — it's a statement. It says your cat's happiness, curiosity, and wellbeing matter enough to invest in. Fresh air, birdsong, sunshine on their face. All of it, without the risks that come with true outdoor life.
For the cat who deserves everything
A catio is love.
The window insert
is the upgrade.
You built them an outdoor sanctuary. Don't let the window be the weak link. Our custom inserts give your catio a seamless, weathertight entry — so your cat can come and go freely while you keep the bugs, drafts, and worry out.
Custom cut to your window
Plexiglass & PVC construction
Made in Roswell, GA
No tools required
The philosophy
Your cat wants outside.
You want them safe.
"A catio is one of the kindest things you can do for an indoor cat."
And when you're ready to take it one step further? A Cat Flap Fever window insert turns your window into a proper passageway — no gaps, no drafts, no improvised workarounds. Just a clean, custom-fit connection between your home and their world.
The premium upgrade
Why our insert is the finishing touch every catio needs
01
A seamless fit, not a workaround
Most catio owners improvise the window connection — plywood, foam, whatever's handy. Our inserts are cut exactly to your window's dimensions, in clear plexiglass and white PVC. It looks intentional because it is.
02
Weathertight from day one
Every insert ships with premium brush weatherstripping pre-applied. Your window stays sealed against drafts, rain, and insects — even with the cat door open and in frequent use.
03
No tools, no damage, no drama
Slide it in, lower your sash, done. No drilling, no caulk, no permanent modifications. Works in double-hung windows nationwide — and it's fully removable for renters or seasonal use.
Featured catio builder
Preferred partner
North Georgia & surrounding areas
Catios of North Georgia builds beautiful, custom outdoor enclosures designed to last — and they recommend our window inserts on every single build. Their craftsmanship gives your cat a world worth stepping into. Our insert makes sure the door to that world is seamless, weathertight, and worthy of the structure around it.
"We partner with Cat Flap Fever because the window connection is too important to leave to chance. Their inserts complete the build."
Visit Catios of North Georgia ↗Ready to complete your catio?
Your cat already has the enclosure. Give them the door to match — custom-made, weathertight, and built to last.
Shop insertsCustom orders · Made in Roswell, GA · Ships within 7–10 business days