woodbrass is selling them
hifihuy528 said he ordered them to review for his youtube channel. I don't know where he bought them from or if he has received them yet.
Picked up a pair recently. I'm comparing them to the NAD Viso HP50 head-to-head to find my new portable headphone. I really like both of them a lot, more than I expected to.
Found this review on headmania for the FS one S