Fleetwood leads the industry by offering insulated glass up to 70 square feet whereas most max out at 55 square feet. But, 70 square feet was not large enough and we therefore have arranged for insulated glass as large as 110 square feet. The new Series 4070-T was designed to handle such large lites of glass but it is not the only one. The Series 3800-T and Series 250-T both can handle glass well in excess of 70 square feet.