NDS 1216 6" Black Riser for 12" Square Catch Basin Drain and Low-Profile Adapter Drain adds up to 6 in. of height to your stormwater catch basin, eliminating the hassle of regrading or awkward piping. The 6 in. Riser can be cut to size with a saw to accommodate your project needs. It’s designed to work with a 12 in. square catch basin and accommodates a 12 in. square catch basin drain grate, or drain cover, on top. The riser is made of high-impact polystyrene (HIPS) treated with UV inhibitors. Hassle-free limited lifetime warranty guarantees the NDS product is free from defects, or we’ll replace it.