Uses pre-existing compression fitting on the outlet side. Electrically operated and uses 24 volts and 2.3 watts. Fits models 220, 224, 400, 400A, 400M, 440, 500, 500A, 500M, 550, 550A, 558, 560, 560A, 600, 600A, 600M, 700, 700A, 700M, 760 and 768.
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