Fernco 4"x4" Flexible Coupling. It is designed for polyethylene to plastic pipe. This coupling connects corrugated polyethylene drainage and irrigation systems to sewer, drain, or DWV plastic pipe. It conforms to ASTM D5926, is ASTM C1173 Specified, CSA B602 Certified, and D5926 Specified. It is suitable for corrugated polyethylene drainage and irrigation systems, farm irrigation systems, golf course drainage, residential areas, storm, and sub-soil drainage systems. With a pressure rating of 4.3 psi and an operating temperature of -30 to 140 degrees Fahrenheit, this coupling ensures reliable performance. Available in 3", 4", 6", and 8" sizes.