The product packaging includes both the "desk clamp" and "grommet" mounting accessories for your choice (supporting desktop thicknesses from 10mm to 70mm):
Desk Clamp: Secures the arm to the edge of the desk using a C-shaped clamp at the base, requiring no drilling or modification of the desk. This method is the preferred choice for most users with standalone desks or height-adjustable desks when setting up their workstation.
Grommet: Utilizes existing cable management holes on the desktop or requires drilling a hole in the desktop, through which a bolt is passed and tightened to secure the arm. This option is especially suitable when the back of the desk is blocked by partitions or when the desk is placed flush against a wall, making the desk clamp unusable.