NDS FWSD69 6" Black Round Surface Drain Inlet with Black Plastic Grate for Flo-Well connects directly to the Flo-Well Dry Well Top Cover and has a 6 in. grate to collect and drain away surface water into the Flo-Well Dry Well System. The surface drain inlet registration tabs are specially designed to ensure proper alignment during installation. 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. The Flo-Well Dry Well System collects, temporarily stores, and slowly releases excess water into the ground. Unlike traditional dry wells which require filling a hole with heavy stone and gravel, the Flo-Well system only needs a small amount of gravel at the base of the tank to prevent scouring. The gravel-free interior provides 2-1/2 times more holding capacity than comparable-sized gravel dry wells.