Natural Light, Tubular Skylight Kit, Pitched, Prismatic Diffuser, 18 inch Large aperture for homes and commercial buildings built at 24 inch on center construction. Illuminates up to 500 sq. ft. Equivalent of up to 1000 watts of Natural light. Hurricane Tested/Approved for Florida hurricane prone areas. Made in the USA. ENERGY STAR Qualified... Tax credits may be available in many applications.