https://wifidb.science/wiki/Cat_Flap_Installers
Professionals should take care of the installation of a cat flap onto your door panel. These doors are usually made of a thin plastic exterior that is bonded to an insulating, soft polystyrene core. It isn't easy to cut through these materials. It's much easier to install the cat flap inside an existing glass pane, or have a new door manufactured with the hole already prepared. A Glazier can do this for you. Easy to Fit Upvc door panels are a great option if you have a cat that you would like to allow it to enter and out of your home with