I bought it years ago on Massdrop (before it was just Drop). There are tons of similar ones out there though.
This one is extremely similar - https://www.amazon.com/Ogrmar-Wood-Headphone-Stand-Holder/dp/B01N9HT3LM/ref=sr_1_3?dchild=1&keywords=wood+headphones+stand&qid=1614128589&sr=8-3