The Sage Horticultural Plug Board is for use with he – Sensor Unit only and the It allows the Sensor Unit to connect to the system electronically and allow signals to be sent to the Solenoid Valve, to let it know when to switch on and off to control the water flow.
The plug on this board is designed to accept the parallel pin style of plug only. this is to avoid any accidental insertion of a 240V plug into the unit and damaging the workings.