Cot PEHD Rainplus 50/88° Rainplus PEHD 50/88° is a high-density polyethylene (HDPE) corrugated plastic drainage pipe designed for underground subsoil drainage applications. It is manufactured with a double wall that consists of two corrugated walls, with a 50 mm (2 inch) spacing between the walls and a corrugation profile of 88°. This pipe is designed to provide superior strength, durability and flexibility, while being lightweight and easy to install. This product is available in a range of sizes, from 50mm to 500mm (2” to 20”).