NDS 918B 6" Satin Brass Round Grate with Collar, Connects to 6" Spee-D Basin and Fittings drains away excess stormwater while blocking leaves and debris from entering and clogging the pipeline. A durable and convenient alternative to traditional concrete drains, the metal grate handles moderate flows of water from lawns, landscaped areas, and patios. Grate has an open surface area of 13.1 sq. in. and flow rate of 40 GPM. The 6 in. Round Grate with Collar connects to the 6 in. Spee-D® Catch Basin Drain and 6 in. sewer and drain fittings for a soil-tight fit. Grate made of brass, collar made of polyvinyl chloride (PVC) treated with UV inhibitors. Hassle-free limited lifetime warranty guarantees the NDS product is free from defects—or we’ll replace it.