TP-Link passive Power over Ethernet (PoE) adapter. This type of adapter is used to supply both data and electrical power to a device through a single Ethernet cable.
It is a passive PoE injector, meaning it does not negotiate power with the connected device and supplies power at all times.
The ports are labeled "DC," "POE," and "LAN."
The "DC" port is for connecting the power supply.
The "LAN" port connects to a router or switch for data.
The "POE" port connects to the device that needs both data and power, such as a wireless access point or an IP camera.