Clamp vs. grommet mount — which should I choose?

A C-clamp attaches to the back edge of your desk and is the most common option; it requires no drilling. A grommet mount passes through a hole in the desk for a more permanent, often more stable hold. Most arms in this list (HUANUO, VIVO, WALI) include both options in the box, so the choice usually comes down to whether your desk has a usable grommet hole and how much rear clearance you have.