This Pella 250 Series unit consists of two double-hung windows mulled side by side into one large 71.5" x 71.5" unit in white vinyl. Both upper sashes tilt in for easy cleaning. Features Low-E 385/189 glass with argon gas fill and tempered glass in the vent sash. NFRC rated: U-Factor 0.25, SHGC 0.20, VT 0.47. High-altitude rated and ENERGY STAR certified. Condition is new — all labels, blue painter's tape, and original shipping skid are intact. Screens included. Subcategory note: this is a double hung mulled unit, not a sliding window.