ErgotronTRACE™ Single Monitor Arm, VESA Desk Mount – for Monitors Up to 38 Inches, 2.9 to 9.8 kg – Matte Black

This is the nicest monitor arm I've ever used- just as well as it's the most expensive too. It's great for areas where people will be walking behind the desk, as it's flat, so there's nothing to walk into.The trellis-style construction makes it very easy to push/pull the monitor nearer or further without it swinging to the side, and the vertical adjustment system is very clever and works well once balanced.It was a little faffy to put together, due to the instructions not matching the box contents completely- it seems that one of the more fiddly assembly stages happens in the factory now. I was all set to start raging about missing bits of my expensive new monitor arm, when I realised that one of the parts was actually an assemblage of some of those shown in the instructions. Once I worked that out, it was relatively plain sailing.It's mostly built like a tank, except for the way that the plastic cable management guides clip into the base. This is a mechanically weak clipping mechanism that will pop out with stiff cables. I had to use some stick-on cable management clips to ensure that the cables didn't keep pulling the guide out of the base. This is a minor irritant only, though- it remains a fantastic monitor arm.Overall, not perfect but really good. I'd buy another.