Concealed door closers tend to be a bit innefficient and you have to take a lot out of the side of the door. We have also seen them pull out if not fitted perfectly. These overhead concealed door closers are all but invisible when the door is closed and the arm can be finished to any stainless, brass or ral colour to make it match in with your scheme when to door is open. Being cam action, they are also among the most efficient door closers on the market which means that the door can be very easy to open but return a good closing force. Ideal for DDA. Ideally you should get your door manufacturer to prep for them but we have seen many fitted on site.