Product description
Power Over Ethernet Passive PoE Adapter Injector + Splitter Kit PoE Cable
Use any CAT-5/5e/6/7 cable to power a device remotely. Use existing power supplies, any voltage up to 48V. The 2.1mm x 5.5mm DC jack and plug allow power to be sent on the ethernet cable and split out again at the remote end. This Power over Ethernet injector allows you to power devices remotely and eliminates the need for 110VAC transformers at the far end.
Since standard Ethernet needs only 2 of the 4 pairs in a CAT-5/5e/6 cable, 2 pairs are unused. Passive POE uses pins 4/5 for plus power,and 7/8 for ground.