NDS 4" Atrium Grate, Black Features enough open surface area to allow water to flow freely in in areas prone to debris collection Made with UV inhibitor RO reduce damaging effects of the elements Made of high performance polyolefin Fits 4-inch sewer and drain pipe and fittings and 4-inch corrugated pipe Atrium grates are ideal for planter beds, mulch areas, window wells, and areas prone to debris collection