This 4-inch atrium grate can be used to drain excess water and direct it to a more water safe area such as a curb or gutter. Atrium grates are ideal for planter beds, mulch areas, window wells and areas prone to debris collection. Can be used with 4" sewer and drain pipe and fittings, 4" corrugated pipe and 4" Triple Wall pipe. Open surface area is 17.0 sq. in.