The Asus ProArt PQ22UC is a 21.6" 3840x2160 (204 PPI, produced by JOLED) printed OLED monitor that at only 1 Kg is marketed as a "portable" monitor. Features include HDR support, 0.1 ms response time, 10-bit color (99% DCI-P3), USB-C input and micro HDMI.
Asus started shipping the ProArt PQ22UC in some countries in Europe in March 2019 for £4,529. The price in the US is expected to be around $5,000.
21.6" 3840x2160 AMOLED