https://dokuwiki.stream/wiki/I....nstalling_a_Cat_Flap
https://botdb.win/wiki/Back_Do....or_With_Cat_Flap_Fit
A cat flap that runs through the wall allows your pets to come out and in whenever they like. You must be careful not to install it too high into the wall. This could lead to energy loss and the possibility of burglars entering your home. Additionally, if you're planning to sell your home in the future, having an opening in your cavity wall could pose an issue for new owners. Glass cat doors offer an alternative that is safer. Easy to install A through-wall