Extend the height of a valve box that's deep in the ground with the 13 in. X 20 in. Jumbo Standard Series Valve Box Extension and Cover. Stack on top of an existing 13 in. X 20 in. irrigation valve box to add 6 in. of height, or use as a standalone box to protect valves, control zone kits, and other irrigation systems in shallow installations. Built to stand up to the elements, pedestrian traffic, lawn care equipment, and potential vandalism, the extension and cover are engineered with structural reinforcing ribs for increased support. The black valve box extension is made of durable high-density polyethylene (HDPE) using 100% recycled materials, and the green cover is also made of HDPE using a combination of virgin and recycled materials. Both the extension irrigation valve box and valve box lid are treated with UV inhibitors to prevent fading and cracking due to sun exposure. The overlapping lid blocks dirt and debris from getting into the valve box, and is marked for irrigation control valve (ICV) use. Convenient slot makes lid easy to lift with a flathead screwdriver. NDS is a leading manufacturer of water management solutions and the trusted brand of professional landscape contractors since 1972. Check out the NDS website or reach out to us for technical support-our friendly, experienced team is here to help make your project a success. Color: Green/Black/Matte.