Review on 🐈 Depets Medium Cat Flap Door with 4-Way Lock (7.5" x 7.8" Outer Size) - Magnetic Pet Door Kit in White, Weather-Resistant for Cats and Dogs by Cody Simmons

This pet door has a built in liner. You simply cut a hole and assemble the two halves. An integrated liner seals the door between the halves. I installed a foam core metal garage door and replaced the included screws with small nuts and bolts. When I ordered it I figured I would have to fabricate something to seal the inside of the door, but no, the built in liner seals the door. The liner slides into the recess, allowing for the installation and sealing of doors of different thicknesses. Mine was 1-5/8" thick and it fit great. The cat used the door with no problem, took to it straight away.