NDS 970 9" Black Plastic Square Grate, Connects to 6" Spee-D Basin, Pipes, and Fittings blocks troublesome particles from entering and potentially clogging your drain pipes with an open surface area of 28.4 sq. in. and flow rate of 87 GPM. Ideal for draining moderate flows from lawns, landscaped areas, patios, walkways, and under downspouts. The 9 in. Square Drain Grate fits on the 6 in. round Spee-D® Catch Basin Drain, 6 in. sewer and drain pipe & fittings, 6 in. single-wall and dual-wall corrugated pipes, and 6 in. Drain Waste Vent/Schedule 40 pipe. 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.