Professional Cat flap installers will install your pet's door in either a door or wall. The wall-mounted version is more secure, since an intruder is unable to get through. It also helps to prevent drafts and lowers your energy costs. The Tasker will mark where the cat flap should be https://www.repairmywindowsanddoors.co.uk/chesham-cat-flap-installer-near-me/