Since then, I have almost no more back pain. It is extremely easy to adjust the monitor height and the optimal angle several times per hour, depending on how you sit straight.
The holes are VESA 100mm * 100mm and 75mm * 75mm, therefore suitable for most monitors. The minimum distance from the top to the bottom hole VESA100 is 26.5 cm, 39.5 cm maximum. It is stable and not prone to tipping, as I thought before buying. The build quality is good, the foot does not look cheap: metal and plastic. The ring and back are covered with synthetic material, the skeleton is but of metal.
Even practical: on the ring you can stow the keyboard and thus make room on the table if necessary.
