NDS 10 8" Black Plastic Round Grate, Connects to 6" Drain Pipes and Fittings. Features 11.5 sq. in. open surface area and 35 GPM flow rate; ideal for draining light flows of stormwater from small lawns, landscaped areas, patios, and walkways. The 8 in. Round Grate connects to the 6 in. Spee-D® Catch Basin, 6 in. sewer and drain pipe & fittings, and 6 in. single-wall corrugated pipe for a soil-tight fit. Made of high-density polyethylene (HDPE) treated with UV inhibitors. Hassle-free limited lifetime warranty guarantees the NDS product is free from defects—or we’ll replace it.