The Walchem WPH620PSNNN-NN controller is now obsolete and is replaced by the Intuition-6 series of controllers. The new series is enhanced, but has similar specs. For reference, here are the specifications of the old model:
Series: WPH600
Relays/Wiring: 100-240 VAC, 2 Opto and 4 Dry Relays, Prewired with USA Power Cord and 2 x 20' Pulse Cables