A non-operating fixed-pane unit built around a single sheet of 3/32-inch glass set into a sealed aluminum perimeter frame. Because there are no moving sashes or weather-stripped tracks, air infiltration drops close to zero, which makes this the quietest and most thermally efficient option in our catalog. Best suited for stairwell openings, gable-end accents, transoms, and any window where ventilation is handled elsewhere and you simply want a second insulating layer at the lowest possible cost.
