DayLite. The DLX15 tubular skylight illuminates up to 150 square feet, while the DLX30 illuminates up to 300 square feet. The DLX30 has a 12-inch double dome on the roof, providing complete isolation from external weather conditions. The dome's "fly-eye" lens and lower diffuser lens are multi-faceted prismatic moldings that trap a second layer of air for additional insulation. 888-329-5483. www.dayliteco.com.