A window may be designed with very different shapes and opening options. A window may have round, triangle, trapezoid and other shapes. A window may be opened by turning, tilting, turning and tilting or it may be a fixed window. All windows are manufactured individually to the dimensions and opening specifications of the customer. To ensure the long service life of a window it is important that the size of the opening part of the window stays within permissible dimensions. Exceeding permissible dimensions may result, for example, in sagging of a window. Our professional sales consultants will advise you upon maximum and minimum permissible window dimensions.