I agree with most other comments. This one isn't sturdy.

Question, How thick is your desk, what material is it made of?

If the desk is wobbly from the start, then I'd definitely recommend a better quality mount. This Ergotech Dual Freedom Arm is a bit more expensive, but the quality is definitely better and it is totally worth it. I have one single arm at home and one dual arm at work. Plus it has the benefit of having built in cable routing channels in it. My home setup.