https://theflatearth.win/wiki/....Post:Cat_Flap_Fittin
The incorporation of a cat flap into your bifold doors can offer many benefits to you and your cat. It also helps to prevent extreme heat or cold from entering your home. First, you need to determine the measurements of your pet to determine the right size door flap you need. This will help you design an opening for the flap that is the right size. Outdoor Access Even those with minimal DIY skills can manage to install a cat flap on an external back door. This will save you the cost and stress of hiring a handyman or carpenter