https://scientific-programs.sc....ience/wiki/Replaceme
You're tired of having climb up to open the door to your pet. A cat flap could be the answer. Pet-flap fitters can install them in any type of door including uPVC or composite doors. They can also fit them into some types of walls. Security Cat flaps are often used to cover doors, however many also have them installed on windows or double-glazed doors. The installation of a cat flap into glass could be a good choice for those who don't want to cut through a wooden or wall door, and is the ideal solution