https://squareblogs.net/pillow....uganda01/cat-flap-in
Cat and dog flaps that are installed with double-glazed doors makes it simple for your pets to move around whenever they like. They also help keep your pet's attention when you are away. It is possible to install a cat flap into an existing uPVC panel or double glazing glass sealed unit, however you'll need a replacement piece with a hole that is pre-made. This can be accomplished by a glazier with the appropriate equipment and experience. Easy to install A cat flap is an excellent alternative