https://www.openlearning.com/u..../lethmackenzie-smdm6
Cat and dog flaps installed in double-glazed units make it easy for your pets to go and come whenever they want. These are also great to keep your pet's attention while you are away. You can install a cat flap into an existing uPVC or double glazing sealed unit. However, you'll need a replacement part with a premade opening. A glazier can do this using the appropriate equipment and training. Easy to install A cat flap is an excellent option to allow your pet to have access to the outside without you having