Grundfos GRU-595916 595916 TLC = Timer, Line Cord, 6-Foot Flow range: 0 - 9 U.S. GPM, Head range: 0 - 6-Foot Motors: Single phase, 115V. Supply Voltage:115-120 VAC, 60 hertz, Contact Rating: 16 amps Connection: 3/4-Inch M by 3/4-Inch FNPT.Maintenance-free, low energy consumption, easy to install, quiet running The Grundfos circulator pumps, Series UP, are specifically designed for heating systems. The pumps are also suitable for circulation of hot domestic water and for circulation of liquid in cooling and air-conditioning systems