The Walchem WCU 400 series controller is now obsolete and is replaced by the WCU6 series controller. The new series has upgraded features; for reference, here is the description of the old model:
Copper Controller
Control: 4 control relays and calibration reminder
Output: 4-20mA
Copper Plating Controller for electroless/microetch applications. With four control relays and calibration reminder and optional analog output.