The Walchem WCM300-145 controller is now obsolete and the closest equivalent is the WBL6 controller. The new WBL6 series has upgraded features; for reference, here is the description of the old model:
two powered relays (one bleed & one alarm), 120 VAC, prewired, single isolated analog (4-20 mA) output, standard electrode (up to 250 psi)
