Features. Type - Flat Top Structural Foam Polyolefin Atrium Grate With Uv Inhibitors. Open Surface Area Is 25.50 Sq. In. Its 33.41 Gpm. Fits Speed Basin. 6 In. Sewer Drain Pipe Fittings. 6 In. Corrugated Pipe.. Size - 6 In.. Dimension - 5.7 X 5.7 X 5.7 In.. Item Weight - 0.6 Lbs.