https://www.openlearning.com/u..../duffyryan-slxv3l/bl
https://britt-cotton-2.federat....edjournals.com/cat-f
Cat flaps allow your pet to move around whenever they want, without you needing to let him in or out. They also help stop your cat from urinating inside the house. It is easier to install the cat flap on a upvc panel than one made of glass, but you will require some expertise and correct tools. Take a look at the Door The installation of a cat flap inside a door can be tricky but as long as you use the correct type of cat flap