The VALUE Gigabit PoE Injector is a so-called PSE, a unit to supply power for e.g. surveillance cameras, and LAN devices such as access points, bridges and routers over Ethernet cable. A PSE supplies the current together with the data in the network cable. It doesn't need no longer an additional own power supply of the device.
Supply of data and power into the network cables
Connectors: 1x RJ-45 port (Data In, Data input), 1x IEC power socket (Power In, input power supply), 1x RJ-45 port (Data & Power Out, output data and power)