A window and door with thermal insulation, characterized by a smooth and slender profile line. The distinctive shape of the profiles, resembling steel constructions, gives the system an industrial and modern character. The minimum visible external width of an inward-opening window is: frame: 1 ³/₈, sash: 1 ³/₈. The system is suitable for fixed windows and inward-opening single-sash windows, with options for tilt and turn functions, opening inward. The system also provides a solution for balcony doors that open inward and outward (with or without a threshold). It stands out in the market due to its unique and modern design. The system is available in a wide range of colors, including the RAL color palette (Qualicoat 1518), structural colors, Aliplast Wood Colour Effect, Aliplast Loft View – colors mimicking stone surfaces (Qualideco PL-0001), anodized finishes (Qualanod 1808), and two-tone options.