A basic cat flap is just a hole you can insert into your door so that your cat can go and go as they like. This design is not very secure and allows burglars access to your home. You should consider upgrading to a home that can be locked or https://cat-flap-in-upvc-door-pan33193.luwebs.com/31309547/adding-a-cat-flap-to-your-bifold-doors