The Power Manager 346 is Designed to Allow Non-Tekmar Products to Interface With a Tekmarnet® 4 Communicating Heating System. It Can be Used in Applications That Use 3rd Party Thermostats, Zoning Devices, or Mechanical Equipment That Requires a Hot Water Demand From The Boiler System. This Product Provides Demand Inputs For up to 4 Different Reset Water Temperatures (High Temp, Low Temp 1, Low Temp 2, Low Temp 3). It Has The Capability of Switching 3 Pump Outputs And Provides Wiring For up to 3 Tekmarnet® 4 Devices, as Well as The 4 Separate Demand Inputs to Create a Heat Call On One of up to 4 Possible Reset Water Temperatures. For Further Information And up to Date Literature Visit: Tekmar Documentation | Tekmar Controls | 346