48V to 12V Active Power over Ethernet (PoE) splitter.
It is used to split a combined PoE signal into separate data (Ethernet) and power (DC barrel jack) lines.
This device typically supports 10/100 Mbps or 10/100/1000 Mbps (Gigabit) data speeds.
It is designed for use with non-PoE devices such as security cameras, VoIP phones, and wireless access point