Flex-Drain 3"x4"x4" Flexible Downspout Adapter. It allows an easier connection with more versatility than standard rigid adaptors. This corrosion-resistant, corrugated, and flexible adapter is suitable for underground use. It has a maximum working pressure of 70 psi, a maximum working temperature of 150 degrees Fahrenheit, and a limited manufacturer's warranty. FLEX-Drain helps you get the job done faster and easier, with professional grade durability and more versatility than traditional corrugated pipe.