The window box provides the connection between the hull and the accommodation system. A piece of flat steel should be laid around the window before the window box is mounted to simplify installation. Window boxes can be supplied with prefabricated cut-outs for windows. A special steel outer sliding frame is used to compensate for tolerances. The window-box body is designed to resist natural vibrations.

A large variety of surface finishes are available; all of them have a removable protective foil to prevent any damage from occurring during installation. The design of the window box and all components used have been tested and approved according to international standards.