the perfect product, packaged well and delivered promptly. I bought a replace catflap unit to replace one which was getting old and tired. This new one was easy to fit in exactly the same hole in the double glazing unit where the old one used to be. With this catflap you have to watch out for two things when fitting. 1) Make sure the door control is in the closed both ways (4) position, or the control wont rotate if you instal it in any other position, and 2) make sure you dont use the supplied longer screws, as this can potentially really damage your new purchase before you even get it installed. The use of screw depends on where you are fitting it, solid wall, glass, wooden door, etc., so be careful and logical. think it through before screwing!