What are the special doors and windows

What we call special doors and windows is to refer to some of the functional, specialized functional doors and windows, such as fire doors and windows soundproofing, doors and windows energy-saving doors and windows, etc., for a door and window system good door and window systems are very targeted features, such as energy-saving heat preservation, then we can choose this kind of doors and windows system like polyurethane profiles produced, then if it is, need to use its soundproofing Function, then we choose to specialize in noise to process the production of Dev soundproof door and window system, and now many systems between the function is overlap, including some soundproof doors and windows, it also has the function of heat preservation, some heat preservation doors and windows also have soundproof function, just focus is not the same