Addressing requirements of larger openings, Ultra Series XL Sterling windows come in sizes up to 48 in. wide x 120 in. tall. Design presents wood on interior and extruded aluminum cladding with durable finishes on exterior. With Class 5 balances for facilitated operation, double hung windows are tested and impact-certified to IPD4 levels and suit any oversized commercial or residential opening. Insulating LoE2-270 glass is standard; customization options are available.