https://writeablog.net/wheelsc....arf0/using-a-cat-fla
A upvc panel with a flap for cats can help to reduce draughts within your home. You can save money by keeping your pet inside and letting the cold air out. is possible to put a cat flap into both upvc panels and double glazing glass sealed units, however it can be more difficult than for timber doors. This is because upvc is available in a variety of thicknesses. Benefits A cat flap that is installed on your door allows you to keep your pet inside or outside the home, while let other people in. It also helps keep out u