Natural Light, Tubular Skylight Kit, Flat, Prismatic Diffuser, 18 inch Illuminates up to 500 sq. ft. - Equivalent of up to 1000 watts. 25 Year Product Warranty. Hurricane Tested/Approved. ICC-ES Listed. High-Impact Acrylic Dome. Unfinished Mill Aluminum finish flat flashing. Domed Prismatic diffuser. Electric light kits are available separately.