Pella Impervia series fiberglass sliding window in white — Pella's premium fiberglass line, stronger and more durable than standard vinyl. XO configuration (operable left panel, fixed right panel). Glass is annealed Low-E 180/189 with argon gas fill. NFRC rated: U-Factor 0.25, SHGC 0.47, VT 0.58. ENERGY STAR certified for all U.S. climate zones and WDMA certified. Rough opening size: 60"W x 72"H. Condition is new — all blue painter's tape, labels, foam corner protectors, and hardware bag are fully intact. Includes window unit and screen.