https://fakenews.win/wiki/Cat_....Flap_Installers_Near
It is possible to install the cat flap inside the door panel made of upvc or double glazing glass sealed unit, although the best option is to buy a new glass pane that has a premade hole installed. Read the instructions that should be provided with the kit for cat flaps, and follow them with care. Make sure that the drawing accurately represents the shape (circle or square). Safety A microchip activated pet panel in your upvc door is a great solution when you have a pet or cat and want to let them out into the garden, but don't want