The Walchem WDIS410-14NU controller is now obsolete and the closest equivalent is the WDS600 controller. The new WDS600 series has upgraded features; for reference, here is the description of the old model:
Disinfection controller, 120 VAC, prewired w/USA power cord and 6" pigtails, single isolated analog (4-20 mA) output, no sensor, integrated datalogging and config file import/export via USB flash stick.