Specialty Recreation NSL208W Skylight Dome Bri-Rus Skylight Dome Skylights are made of high performance thermoformed polycarbonate to be long lasting and easy to clean When choosing a Skylight, measure your rough hole opening as well as the overall exterior size There is a size to replace most manufacturer's original equipment White color, Hole size 20 Inch x 8 inch; flange size 24 inch x 11 Inch; height 4 inch