This 400 Series (24VDC/5.4W) is a 4-way spool valve with reverse pilot operated by a small, direct operated 4-way solenoid valve with light kit – a one-off in air valve manufacturing.  The 4-way pilot means a low minimum operating pressure – no piston adapters – and minimal resistance to shifting.  The balanced design in the pilot means shifting forces are consistently high and response times are repeatable regardless of inlet pressure fluctuations.   View installation instructions for this solenoid valve on the “RELATED FILES” tab.