Why are they needed?
They keep the screen from falling in your lap when it’s tilted forward.
They also clean up cables from lying on the desk.
If clamping a XOOT system to the back of a desk, the optimal desk widths range from 24″ (60 cm) to 32″ (80 cm).
For wider desks, the clamp can fit through a 2″ (8 cm) or larger hole.