NDS 20 Plastic Round Grate, 8-Inch, Green Use to drain excess water and direct it to a more water safe area such as a curb or gutter Can be use in large lawn areas, large landscape areas, patios and atriums Use with NDS Spee-D basin, 6 in. sewer and drain pipe and fittings and 6 in. corrugated pipe Open surface area 11.5 square inch UV inhibitors help prevent cracking and fading due to exposure to the elements