The opening unit, which has narrow profile face widths that perfectly meet all the architectural requirements, is a design characteristic of the Schüco AWS 75 PD.SI window system. What is more, the interior face of the profiles is flush to the window with the sealing being hardly visible, thus giving a unified appearance to the frame. The system offers a range of attachments to the building structure, such as, for example, the option to realise a concealed drainage system. The windows are equipped with built-in anti-burglar properties.