There are a variety of solenoid valves to choose from: 5/2-way valve, single solenoid, 5/2-way valve, double solenoid, 5/3-way valve, empty valve position, etc, with large flow rate, long life, low opening pressure, more reliable characteristics. A variety of bus sizes with a maximum of 24 valve positions are also available, allowing quick in-island and out-island pilot functions by interchanging plugs and pins.