Headroom Micro Portable Headphone amp + DAC. They can be powered by 9V batteries. Very portable.
They are in excellent condition. I don't see any cosmetic issue and functionally they work flawlessly. Very light use in my office. Sounds good with my AKG702.
I have original packaging, power adapters, strap, and cardas interconnect between the dac and the amp. I prefer to sell it as a set. They are about 2 years old.
Asking $400. PM me if you are interested.