Approve the monitor, arm, mounting hardware, and exact desktop as one assembly; a matching screen size is not enough.
A monitor arm needs to fit two things: the display it supports and the desk it attaches to. It also needs to place the screen where the user can work. A purchase based only on screen diagonal leaves all three questions partly unanswered.
Treat compatibility as an approval of a complete assembly. Record the monitor, arm, attachment hardware, desktop, base, and neighboring accessories. If any of them changes, revisit the relevant checks before installation. This is a purchasing checklist, not authorization to modify a desktop or improvise mounting hardware.
Begin with the display's actual identity
Get the monitor's exact model number and its manufacturer documentation. Find the weight without its original stand, the mounting interface, permitted orientation, mounting-screw requirements, and any adapter restrictions. Include attached accessories when the arm manufacturer says they count toward supported weight.
Do not use shipping weight or assume a similar-looking screen has the same mounting arrangement. If the manufacturer supplies no suitable mounting interface, ask whether an approved adapter exists. An unverified adapter is an unresolved compatibility issue, even if its holes appear to line up.
Give the arm supplier the monitor model and ask for written confirmation when the combination is not clearly covered by its documentation.
Match the entire supported range
Read minimum as well as maximum supported weight. Ergotron's LX Pro series specification sheet, for example, gives the Desk Arm a 4–22 pound range and identifies the supported 75 × 75 mm and 100 × 100 mm mounting patterns. Those are specifications for that model family and document, not universal arm requirements. Ergotron LX Pro series specifications
Ask about any depth, shape, or center-of-gravity restrictions that apply to a thick or curved display. Ergotron's LX Pro Dual Stacking page expressly notes that monitor depth can reduce capacity. It also provides individual-display and combined load limits. Read those qualifications rather than transferring a total rating to each display. LX Pro Dual Stacking specifications
When documents disagree, do not select the more favorable number. Ask the manufacturer which revision and specification govern the exact order.
Verify the top and mounting location
Send the desk supplier the proposed arm and mounting location. Request confirmation that the selected top construction, thickness, edge, support structure, and attachment method are suitable. A clamp's opening range does not by itself establish that the desktop can support the assembly.
Inspect the underside and rear edge. Check for an apron, support rail, cable tray, beveled edge, screen bracket, or other obstruction that could prevent the clamp from sitting as designed. Confirm that there is access for installation and later inspection.
For a through-surface mount, establish whether an existing opening is compatible or whether an approved factory provision is available. Do not drill because an installation video shows a different desk being drilled. Written approval should address location, required support, and warranty implications.
Product drawings can reveal conflicts that a catalog photograph misses. The Migration SE specification guide illustrates configuration-specific accessory and worksurface relationships; obtain the equivalent document for the desk actually being purchased. Migration SE specification guide
Check the required movement, not only the maximum reach
Draw the screen's intended position with the employee seated and, where applicable, standing. Mark the distance from the mounting point to that position. Then ask what space the arm occupies when folded, extended, and turned.
Check these situations in a representative setup:
- The primary screen centered on the main task.
- Both displays in their intended daily arrangement.
- A screen turned toward a colleague, if that is part of the work.
- The desk at its approved lowest and highest working positions.
- The arm near a wall, divider, shelf, or neighboring workstation.
- A user changing between portrait and landscape, if supported and needed.
OSHA recommends placing a monitor directly ahead for primary viewing and choosing a position that does not require awkward leaning or head posture. Use the employee's actual work to check the result. An arm that attaches successfully can still fail to provide useful positioning. OSHA monitor guidance
Use a compatibility worksheet
Keep a row for each display, even when purchasing a matching pair. Record the evidence, not simply a tick beside “compatible.”
| Check | Record before approval |
|---|---|
| Display | Model, supported mounting interface, weight without stand, attached accessories |
| Arm | Exact part number, weight range, dimensional restrictions, movement envelope |
| Attachment | Clamp or through-surface hardware, manufacturer-approved method |
| Desktop | Model, construction, thickness, edge profile, approved mounting position |
| Conflicts | Rails, screens, trays, wall clearance, and installation access |
| Desk load | Confirmation that the full assembly is within the desk's applicable limits |
| Cables | Actual route through arm movement and desk travel |
| Decision | Approved, approved after change, or unresolved, with supporting documents |
Close the order with an installed check
Have the authorized installer follow the instructions for all components, including adjustment and inspection requirements. Check normal positioning with the actual display and cable set. If an arm will not hold its approved load or a clamp does not seat correctly, stop using the setup and contact the supplier rather than adding makeshift spacers or excessive force.
Save the approved worksheet with the workstation standard. The next monitor refresh is then a straightforward compatibility review instead of a search for the person who remembers why those arms were selected.
Sources & editorial review
This is a research-based buying guide. It does not represent hands-on product testing. Prices, product specifications, supplier terms, and availability can change.