Advertised as the world's most powerful palm-sized 4K mini PC, the GMK NucBox surfaced in multiple reviews a few months ago and was supposed to become available for purchase in late October. Now, this minuscule mini PC is finally up for purchase starting at US$219 (Intel Celeron J4125, 8 GB RAM, 128 GB SSD).
https://www.notebookcheck.net/2-4-inch-GMK-NucBox-mini-PC-is-finally-available.508142.0.html