https://chessdatabase.science/....wiki/Cat_Flap_Instal
Install a cat flap if you want your pet to be able to leave and come back whenever they like without having to open the front door. However, you must employ a licensed professional to install one. They are able to handle the complexity of fitting various types of cat flaps to various walls and doors. Installation With a cat flap your pet can come in and out of the house at will, without needing to open the door. The variety of pet flaps available on the market is extensive, ranging from microchip-proof and bite-proof