NDS 1211G 12-Inch Square Grate, Black 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 Fits onto NDS 12" x 12" Catch basin Open surface area 50.76 sq. in Will accommodate 155.28 GPM with 1/2" of head