https://squareblogs.net/format....dog3/why-install-a-d
If you have a cat or dog, installing a pet flap inside your French or patio doors is a great idea. It lets them enter and exit without you needing to open the door. There are a variety of options for cat flaps made to fit into uPVC or composite doors as well as wooden doors. Some have a four way locking system that can be set to exit only, in-only, or open. Installation Cat flaps are a great way to let your cat into and out of your home without having to open the front door every time. This is particularly benefic