Keep the line free of dirt and debris and prevent mineral buildup with the Automatic Flush Valve. This device makes it easy to flush out the line, which is essential for proper care and maintenance of the drip irrigation system. Fits onto the end of 0.940 in. OD tubing, but unlike an end cap it does not need to be removed to flush out the line. When the water pressure drops low or is turned off, the valve automatically opens to drain the line, and closes when done to keep bugs out. Made of durable plastic treated with UV inhibitors.