Advanced Drainage Systems is the world's largest producer of corrugated HDPE pipe and related drainage products. ADS serves the storm and waste water industry through a global network of 56 domestic and international manufacturing plants and 27 distribution centers. In addition to its flagship N-12 pipe, the company offers a complete line of fittings and other accessories including, Nyloplast drainage structures, and various geotextiles. Made from high-density polyethylene, the 4 in. x 100 ft. Corex Polyethylene Pipe is perforated and then enveloped in knitted polyester black sock to prevent migration of soil into imported backfill and the pipe.