Abstract: A window for use in buildings or other enclosed areas is structured to open horizontally relative to the building or window casement and comprises a screen-like enclosure between the window casement and the window frame which limits the amount of moisture or dust that can enter through the window when in an open position. Further, the window is particularly structured to provide light, ventilation and an unobstructed view while providing a high degree of security to prevent breakage or burglary.