Top positive review
Holds the Acer X34 Predator just barely for Portrait mode
August 20, 2017
I purchased this mount to replace the terrible mount that came with the Acer X34 Predator monitor. I have a simple IKEA desk with a cable management tray under it. I had to move the management tray as you need 3-/18" clearance in order to spin the knob to tighten it. If your desk has a small narrow lip, you won't be able to mount in using the clamp mechanism. I suppose you can get away with 3", but please be aware of this. I'm not referring to the thickness of the desk, but rather the distance from the back of your desk to the back wall of your desk if your desk has one.
The 34" ultrawide monitor I have is just barely able to stand on my desk in portrait mode using this arm. You need to mount height ring as far up as you can (with the top still flush). Spinning the monitor will require you to first tilt the monitor up before you can rotate the screen. However, it is easy to move the monitor yet maintain stable positioning.