As I am selling my HE6se (https://www.head-fi.org/classifieds/hifiman-he6-he6se-adorama-edition.64817/) I no longer need the Hifiman HE adapter to connect them to my power Amp speaker taps. I have the original box and will double-box for shipping. My asking price includes PayPal fees and shipping to the contiguous 48.
I will respond to reasonable offers, particularly if you are also interested in the HE6se.