This solenoid valve helps users control the flow of water. It would make a great addition to the robotic gardening projects. Normally, the valve is closed. When 12VDC is applied to the two terminals, the valve opens and water can push through. Notice that the liquid can only flow one direction. There are 2 kinds of this solenoid valve for your selection. The “Inlet Valve” has working pressure 0.02 Mpa – 0.8 Mpa, used for water influent, while the “Drainage Valve” 0-0.2 Mpa, used for Drainage. Please select the right one you need.