Cot PEHD Rainplus 75/88° Cot PEHD Rainplus 75/88° is a high-density polyethylene (HDPE) corrugated drainage pipe designed for use in residential and commercial applications. It is made from a combination of HDPE and polypropylene, with an inner layer of high-density polyethylene and an outer layer of polypropylene. The corrugations in the pipe provide a greater strength and allow it to be more flexible, allowing it to be used in tight spaces. The pipes are available in a range of sizes and can be used for a variety of applications, including stormwater drainage, irrigation, and sewer and drainage systems.