Pella Impervia 48x48 inch black aluminum sliding window in like new condition, still in original box. Features a vent/fixed sliding configuration, SunDefence low-e glass coating, argon gas fill between panes, a visible transmittance of 0.40, and a solar heat gain coefficient of 0.21 for strong heat rejection and energy efficiency. The Impervia line is known for its fiberglass-reinforced construction and durability in extreme climates. Includes the sliding window unit only. Dimensions: 48 x 48 in. No damage or missing parts reported.