The Interespace Industries ATBB Analog termination to unBal Box. This is the PCBB in reverse-balance line in to unbalanced out on 3.5mm jack.
This is for use on systems that have a mini jack input for stereo line or for stereo mic input. The Ground will isolate the ground from the source for rejection of ground loop hum.
The Pad will pad the signal to about 36dB. The Stereo/ Mono switch will join the output pairs via a resistive element to give both channels the same signal.