NDS Drainage Kit Square w/ Grate 12 in.. Don’t let excess stormwater turn your property into a soggy, mucky mess. The 12 in. Low-Profile Adapter Kit takes care of heavy flows from lawns, landscaped areas, under downspouts, patios, and walkways and helps prevent mud slicks, slippery mildew, and costly water damage. Kit includes a 12 in. square low-profile adapter made of high-impact polystyrene (HIPS), square grate made of high-density polyethylene (HDPE), and one outlet adapter. The low-profile adapter is ideal for spaces where a traditional catch basin won’t fit, and the drain grate defends the drainage system by blocking leaves, dirt, and other debris from entering the pipeline. Included outlet adapter connects to 3 in. & 4 in. sewer and drain, single-wall corrugated, triple-wall, and DWV/Sch. 40 pipes.