I've been using 2 of these to mount two different monitors. Make sure your have vsea mounts on whatever you want to mount. The very smallest the clamp goes is about 1\ or 1 1/2\" so if your desk isn't that large then just put a thick cardboard piece between the clamp and the desk. It's not considered the safest option but it gets the job done. I've had mine on for a good 3-4 months like that and there's no sign of the monitors slipping from the desk. Make sure to really REALLY tighten the clamp on first installation.If you can spend the extra couple dollars