louvres

A louver (American English) or louvre (British English), from the French l’ouvert; “the open one”) is a window, blind or shutter with horizontal or, less often, vertical slats, that are angled to admit light and air, but to keep out rain, direct sunshine, and noise. The angle of the slats may be adjustable, usual in blinds and windows, or fixed. Modern louver windows comprise slats of glass, opened and closed with a metal lever, or they may be shutters of wood, plastic or other material.