are held on the tube so height adjustment with monitors attached is much easier, even if it's just adjustment in preset increments - add Include a clamp in the package to secure the base to the table, or make it clear that two people are required for installation. I didn't have any help, but I did have a small clip hanging out. Otherwise the whole thing will tip over when you hang up the first monitor. - not strong enough to satisfactorily hold two monitors of different weights on the same arm - the swivel has too much play back and forth so the monitors still dangle like sheep's tails no matter how hard you tighten the tilt adjustment to the hell. It takes a long time to compensate for this tendency. To conclude on a positive note, the price is decent, the overall quality is good, it comes with lots of screws, washers etc and once perfected it works exactly as expected. The cable management clips also feel comfortable.