These products use a 24 volt power supply and Passive or Active Power Over Ethernet (PoE) Injector to add power to ethernet cable. We use 24 volts to insure low loss, then step the voltage down to 12 volts with a DC-DC convertor, splitting the power and data. The PoE splitter has a 2.1mm DC plug that fits most 12 volt non-PoE cameras, and we have adapters for other models.