The Walchem WDP440-12NN controller is now obsolete and has been replaced by the WDP440-12NU controller which now has integrated USB datalogging and software upgrade capability. Otherwise, both the WDP440-12NN and the WDP440-12NU have the same specifications with 4 pulse proportional outputs & 1 dry contact dedicated alarm, 120 VAC, pre-wired with 20 ft. cables for E Class pumps, two isolated analog (4-20 mA) outputs, no electrode, no USB.
Please click here to view and/or purchase the new replacement controller and to view literature.