UH1822A module is stereo headphone amplifier with volume control on the front panel, connecting with CSP transceivers and receiving the audio signal from pair B and C of UTP RJ-45. The headphone output is standard 3.5mm mini jack on the front panel.

UH1822A module could be powered from the connected CSP transceiver module.
The signal and power also could be provided to all the connected modules by Pair D of UTP CAT5 cable.