Advanced Drainage Systems is the world's largest producer of corrugated HDPE pipe and related drainage products. In addition to N-12 pipe, the company offers a complete line of fittings and other accessories, including Nyloplast drainage structures and various geotextiles. The 4 in. Snap Tee Coupling is designed to join 4 in. single-wall corrugated polyethylene drainage pipes. The coupling snaps on for an easy connection. Color: black.