https://pattern-wiki.win/wiki/....How_to_Choose_a_Cat_
Cat flaps allow your pet to come and go whenever it wants. You can select a locking flap to keep other cats and animals from entering your home. Installing a cat flap onto the bifolding door is feasible as long as the door frame is made from toughened glass. The frame must not be damaged or rotten. The procedure is basically the same as installing a cat flap in an wooden or uPVC door. Easy to install Adding a cat flap to your bifold doors allows your pet to go in and out of the house without hassle, and without having to