https://algowiki.win/wiki/Post....:Using_uPVC_Cat_Flap
Cat and dog flaps that are installed in double glazing makes it simple for your pets to go and come whenever they like. They also help in keeping an eye on your pet whilst you are away from home. It is possible to fit the cat flap onto an existing uPVC panel or double glazing glass sealed unit, but you'll need to replace the piece that has a hole already made. A glazier is able to do this using the appropriate equipment and training. Easy to install Having a cat flap in your home is a great option to give your pet access to