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Cat and dog flaps in double-glazed units makes it simple for your pets to go and come whenever they like. They also help in keeping an eye on your pet while you are away from your home. It is possible to put the cat flap onto an existing uPVC panel or double glazing glass sealed unit, but you'll need to replace the piece with a premade hole. This can be done by a glazier with the proper equipment and skills. Easy to install A cat flap is a great option for allowing your pet access to the outdoors