Both the inlet and outlet of the 4040 solenoid Valves are threaded 7/16"-24 UNS for accepting a compression fitting for ¼" tubing. (24V | 2.3W | 60Hz | Blue). The humidifier water solenoid Valves 4040 is specifically manufactured to fit for A.prilaire 220, 224, 400, 400A, 400M, 440, 500, 500A, 500M, 550, 550A, 558, 560, 560A, 600, 600A, 600M, 700, 700A, 700M, 760 and 768 humidifier.
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