The XPRO model 900 series is a valve top mounted proportional valve controller designed to drive proportional valve solenoids of 12v or 24v.  It is ideal for use in both mobile or static applications and employs state of the art surface mount technology to give precise control of valve position, compensating for variations in coil resistance and power supply fluctuations.  Control is via an external potentiometer connected to the voltage reference supplied or from an external 0-10V input.  The unit comes with 1 metre of cable for easy installation and the compact nature of this range of control makes it extremely versatile and excellent value for money.