Orbit 1/2" x 10' Underground Sprinkler Riser Flex Pipe. This high-grade polyethylene plastic tubing is used for installing sprinkler heads without the use of risers. It has an outside diameter of 1/2-inch and an inside diameter of 1/2-inch, with a recommended working PSI of 80 and a maximum working temperature of 140 degrees Fahrenheit. It is 10 feet long and is black in color.