https://fkwiki.win/wiki/Post:Cat_Flap_Fitters
It is possible to fit the cat flap inside a door panel made of upvc, or a double glazing glass sealed unit however the best choice is to have a new glass pane with an already-made hole. Follow the directions included in the kit. Make sure that the template sketch accurately depicts the shape (circle or square). Safety If you have a dog or cat and want to let them in the garden without having the door open, a microchip activated pet flap in your door's upvc panel is a great choice. It will only allow your pet inside, while preventing other a