Full Glass Cat Door for Window,32"-37" Adjustable Width,1-Min Install | 4 Locking Modes,Aluminum Frame,HD Glass,Magnetic Closure,Weatherproof Sliding Pet Door Window Insert for Cats

I made it out of a leftover piece of cabinet board and a $12 cat flap! There are a few window ones on Amazon for $75 that I'll spring for if this one fails though. https://a.co/d/07ZGTtBW