https://www.openlearning.com/u..../daleelliott-slw3dk/
https://horner-serup.mdwrite.n....et/adding-a-composit
Installing a pet flap on your French or Patio doors is a good idea if you own pets such as a cat or dog. It allows them to get in and out without having to open the door. There are a myriad of cat flaps available to be used with uPVC composite or wooden doors. Some come with a 4-way locking system which can be set to allow exit only, in-only, or open. Installation Cat flaps are an excellent way to let your cat into and out