https://writeablog.net/windows....moke6/doors-with-cat
If you have a cat or dog installing a pet flap inside your French or patio doors is a good idea. It allows them to get in and out without having to open up the door. There are a variety of cat flaps available that are designed to fit into uPVC or composite doors as well as wooden doors. Some come with a 4-way locking system that can be set for exit only, in-only, or open. Installation Cat flaps are an excellent method of letting your cat in and out of the house without having to open the door each time. This is particularly useful