This is a Fiio X5 player + JDS Labs O2 headphone amp combo. This Fiio X5 can play most of the audio formats: MP3, WAV, APE, DSD etc. It has the digital output and can be used as the source in the audio system.
I bought both of them new but only used it for less than 100 hours. Not much usage signs on the body, but the rubber wheel is a little sticky due to storage. I couldn't test JDS O2 amp now because I can't find its power supply. But it was working before, so the condition should be fine.
Comes with a high quality audio cable, and boxes.
You need to buy the power supply directly from JDS website or maybe Amazon. Please note that you need a 15V
AC adapter, not the regular DC one. Please refer to the power supply photo (which is
not included!) for details.