To make your underground sprinkler system also function as a low-flow drip irrigation system, this is the adapter you need. The 1/2 in. FPT X 1/4 in. Sprinkler Riser to Drip Tubing Conversion Adapter threads onto the sprinkler riser & outlets through the sprinkler head on top as well as through the 1/4 in. supply tubing or dripline inserted into the side compression ring. A filter washer inside the adapter ensures a watertight fit and screens out particles before they can clog the system. This adapter is made of acrylonitrile butadiene styrene (ABS) treated with UV inhibitors to prevent cracking.