https://www.openlearning.com/u..../troelsenlindgren-sl
https://yamcode.com/fitting-a-cat-flap-104
Installing a pet flap on your French or Patio doors is a good idea if you have a dog or cat. It allows them to enter and exit without you having to open up the door. There are many options for cat flaps made to fit into uPVC, composite, or wooden doors. Some even come with a four-way locking system that can be configured to let out only by entering only the direction of opening, or in both. Installation Cat flaps are a great method to allow your cat access i