https://www.openlearning.com/u..../ericksonnewman-smfh
https://bynum-snow.mdwrite.net..../fit-a-cat-flap-in-a
A cat flap is a tiny door that allows your pet to arrive and leave the house as they please. It can be installed in doors, windows, and even walls. It is opened when a cat pushes through a section of its body. Microchip cat flaps recognize the unique microchip of your cat to unlock the door. Infrared and magnet cat flaps require your cat to wear a collar that has an infrared or magnet device that will activate them.