The spec's claim up to 30" monitors are capable of being mounted on this Arm, however, I have two 27" and two 15" monitors mounted and even this weight is enough to cause the 27" screens to sag vertically. you will need to be aware of how top-heavy this mounting will be, with four devices attached, the table you are mounting this to, will need to be extremely stable and heavy so the fully loaded ARM doesn't tip the desk. Also, clearance between the bottom screens and the desk is not as much as I would have wanted but I am unable to raise them higher as the mounting pole isn't tall enough.