VESA compatibility, spring vs bolt adjustment, desk mount types, and weight capacity, we expla in what the specifications mean and which monitor arm features actually matter for your setup.
Before buying a monitor arm, confirm your monitor has VESA mounting holes on the back: Remove or fold down the stock stand Look for four threaded holes in a square pattern on the back of the monitor Measure the hole spacing: 75mm x 75mm (VESA 75) or 100mm x 100mm (VESA 100) Monitors without VESA holes (some older monitors, some all-in-ones, most iMacs prior to 2024): cannot use standard arms without a VESA adapter bracket.
Monitor arm weight capacity must exceed your monitor's weight.
Two places to find monitor weight: Spec sheet from the manufacturer (look for "weight without stand") The shipping box, which lists gross weight, subtract approximately 0.5-1kg for packaging 34-inch ultrawide: 7-10.5kg The arm's rated capacity should exceed your monitor's weight by at least 1kg.
A spring arm at exactly its weight limit will struggle to hold position as the spring wears.
Three desk measurements matter for monitor arm compatibility: Desk thickness: C-clamp arms typically support desks up to 3.5-4 inches thick.
Standard desks are 24-30mm (about 1 inch).
Standing desks (Uplift, Fully Jarvis) are often 70mm (2.75 inches).
Very few home desks approach the C-clamp maximum.
Desk depth: the arm adds depth, the monitor moves closer to you.
Spring (gas lift) arms: counterbalance the monitor's weight.
Repositioning requires only light pressure.
The spring must be tuned to your monitor's weight using a tension adjustment (typically a hex screw in the joint).
Once tuned: the arm holds any position without tools.
Spring arms work best when: You have a sit-stand desk and adjust height multiple times per day You work in different positions throughout the day (sitting, standing, close for detailed work, far for presentations) You will use the arm for multiple years with potentially different monitors (requires re-tuning for new monitor weight)
Monitor arms handle cables in one of three ways: Internal routing: cables pass through channels inside the arm.
From the front: no visible cables at all.
From the back: a single cable run exits the arm near the desk and connects to your equipment.
Ergotron LX, Ergotron MXV, and premium alternatives use this approach.
External clip routing: cables clip along the outside of the arm using plastic clips or wire ties.
Dual monitor arms mount from a single pole or clamp and support two monitors independently.
Monitor size matching: dual arms work best with two monitors of identical or very similar size and weight.
Mixed-size setups (one 27-inch, one 24-inch) work mechanically but require independent tension adjustment for each arm.
Portrait/landscape mix: many dual arms support rotating one monitor to portrait orientation (useful for code, documents, chat).
Confirm the arm supports rotation before buying for this use.
The practical result of a correctly set up monitor arm: Top of screen at or slightly below eye level, reduces neck flexion Monitor positioned directly in front, not angled, reduces cervical rotation Distance from eyes adjustable, typically 20-30 inches is comfortable for most users Screen angle (tilt) adjustable to eliminate glare from specific light sources
Our picks
As an Amazon Associate I earn from qualifying purchases. Picks are based on manufacturer specs, independent reviews and owner reports.
HUANUO
An aluminum gas-spring dual arm for two 17 to 32-inch monitors with clamp or grommet mounting.
Ergotron
25 lb capacity handles even heavy 38-inch curved ultrawides
Keep researching
