This 4 in. HDPE External Snap Coupling is designed to snap into place for making quick and easy connections. The coupling''s high-density construction is made to resist corrosion and abrasion for durability. 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.