https://informatic.wiki/wiki/Fitting_a_Cat_Flap
It is possible to put an apron flap inside an upvc panel or double glazing sealed unit. However, the most effective alternative is to install a new glass pane with a hole that is already made. Follow the directions that came with the kit. Ensure that the shape drawn (be it square or circle) is accurately depicted on your template drawing. Safety A microchip activated pet door in your door made of upvc is a fantastic option when you have a pet or cat and would like to let them out into the garden, but don't want to leave the door open. It