A ventilator formed from molded parts and a simulated structural panel formed from molded parts, said ventilator and panel used in combination or separately. The panel has four molded frame parts with integrally formed structures to support a screen, a window pane, a louver assembly, and a roller for opening and closing the louver assembly. The frame parts have integrally formed interlocking members for joining and bonding the frame parts together. The louver assembly includes a plurality of louver members with integrally formed brackets which are pivoted to the side frame parts and to common links, one of which common link is operated by the roller to open and close the louver members. Molded split stem pivot shafts are used for the roller and louver assembly. Other integrally formed parts on the molded frame part are provided to tilt the window pane in open position, to provide rigidity, and interlocking of the frame parts, to provide interior and exterior flanges for the ventilator, and to provide other features of advantage in the substantially all plastic ventilator.
