https://timeoftheworld.date/wi....ki/Adding_a_Cat_Flap
https://fakenews.win/wiki/Upvc...._Door_Panels_With_Ca
http://brewwiki.win/wiki/Post:....Replacement_Upvc_Doo
Cat flaps allow your pet to move around whenever it wishes. You can opt for a lockable flap to keep other cats and animals from entering your home. Installing a cat flap onto a bifolding door is possible as long as the door frame is made from toughened glass. The frame should not be damaged or rotten. The process is largely the same as installing one in a wooden or uPVC door.