Controlling the power circuits of as many as four separate devices is a snap with this relay module. Each mechanical relay can control a seperate circuit of up to 210W of DC power or 1750 VA of AC power. This module requires an external power supply, which is isolated from the VINT port in order to improve stability by preventing ground loops. The relays by nature also isolate the load circuit from the control circuit, meaning you don't have to worry about voltage spikes in the load damaging your VINT Hub or computer. The REL1000 connects to a port on a VINT Hub.