https://www.openlearning.com/u..../mcneildowns-sm01f3/
Are you fed up with having to get up and down to open your door for your pet? If this is the case, a cat door could be the solution. Pet-flap fitters are able to install them on any type of door that is available, including uPVC or composite doors. They can also install them in certain types of walls. Security Cat flaps are typically fitted to doors, but many also install them in windows or double-glazed doors. If you don't have a wood door or wall, having one installed into glass is a great option.