Grundfos 599388 Timer is designed only for use with specified Grundfos Series UP circulators installed in indoor hot water service systems. Applicable Series UP models include all single speed UP 10-15, 1-phase, 115 volt, 60 hertz pumps with date codes of 0528 and higher.The Grundfos Timer control is designed to turn the circulator on and off at preset times, allowing the user to select operation of the circulator during high use periods of the day.Technical Specifications of Grundfos 599388 Timer Supply Voltage 115-120 VAC, 60 hertz Contact Rating 16 amps Ambient Temperature -4F to 175F Shortest Switching Interval 15 minute increment Switch Modes"Timer", "ON" Override, "OFF" Override Protection Clear plastic cover for dust and moisture protection of the clock faceDocumentationGrundfos 599388 Timer Installation and Operation(pdf)