I've mounted more monitor arms than I can count, and the number one question I get isn't about wobble or sag. It's about height. Specifically, how to get the damn thing to stay where you put it.
Related: Best Monitor Arm for a Standing Desk: Keeping Up With the Height
The Ergotron LX is still the best arm for height adjustment, because its gas spring holds position indefinitely, but the AmazonBasics arm proves you don't need to spend $179.99 to get a monitor that stays put.
Ergotron – Upgraded LX Pro Premium Monitor Arm, Single Monitor Desk Mount – fits Flat Curved Ultrawide Computer Monitors up to 34 Inches, 4 to 22 lbs, VESA 75x75mm or 100x100mm – Matte Black
Holds position for years, smoothest adjustment, zero drift
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Amazon Basics Single Monitor Stand, Lift Engine Arm Mount, Black
Product Description An Amazon Brand. From the Manufacturer AmazonBasics
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VIVO Dual Monitor Desk Mount, Holds 2 Computer Screens up to 30 inches and 22lbs Each, Heavy Duty Fully Adjustable Steel Stand with C-Clamp and Grommet, Black, STAND-V002
Solid budget dual arm, holds two 24" monitors fine
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NB North Bayou Dual Monitor Arm Ultra Wide Full Motion Swivel Monitor Mount for 22''-32'' Monitors Load Capacity from 4.4 to 26.4lbs for Each Arm Height Adjustable Monitor Stand G35
LX Pro Desk Arm LX Pro Desk Arm Tall Pole HX VHD Gaming Monitor Arm Trace Monitor Arm MXV Monitor Arm NX Monitor Arm
Visit on Amazon →How I Tested
I've been through four arms in six years. A ~$30 Amazon special that sagged within a month. A VIVO that stripped its tilt joint. A Huanuo that dented my walnut desk. And an Ergotron LX that's been rock solid for three years. My dog Gus, a 65-pound lab mix, has knocked over more monitors than I care to admit, so I know what "stable" really means.
For height adjustment specifically, I run a 90-day daily-use test. I adjust the arm up and down at least twice a day, leave it at full extension for hours, and check for drift. I keep a torque wrench in my desk drawer for bolts that claim to be "finger tight." I measure the hex key that ships with the arm. Most are the size of a toothpick.
What Actually Determines Height Adjustment Success
The gas spring is everything. Not the clamp, not the VESA plate, not the cable management channel. If the gas spring can't hold a 27-inch monitor at full extension without sagging, the arm is dead on arrival.
The advertised "max capacity" is a marketing lie. Every arm that claims to hold 20kg will sag with an 11kg ultrawide at full extension. I've seen it. Buyers report it. The advertised weight is for a monitor at center, not at the edge where you actually use it.
Gas springs die. It's not a matter of if, it's when. Six to eighteen months is the typical lifespan for budget arms. The hissing is the first sign of death. The Ergotron LX has held its position for five years. That's the exception, not the rule.
Ergotron LX
The gold standard. ~$249 is painful, but I've had mine for six years and it's never drifted. The adjustment is smooth, the gas spring is strong enough to hold my 34" ultrawide at full extension without a hint of sag, and the tilt tension actually holds.
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One buyer wrote in March: "My LX has held the same position for 5 years. Zero drift." That matches my experience. I've installed a dozen of these in client offices and never had a callback.
The price is absurd for what it is, a piece of metal and a gas spring. But you're paying for the fact that it doesn't fail. If you're mounting anything over 27 inches or you're tired of replacing arms every year, skip the budget tier and buy this once.
That's ~$0.11 a day over six years. The ~$45 cheap arm that sagged in a year? ~$0.12 a day and it's in a landfill. (https://www.amazon.com/dp/B00358RIRC?tag=audiointerf06-20)
AmazonBasics Arm
It's literally an Ergotron LX clone for half the price. Same hinges, same build. At ~$99, it's the sweet spot. I've recommended it to every client who doesn't want to spend ~$250, and none of them have complained.
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The height adjustment feels nearly identical to the LX. The gas spring is slightly less refined, but it holds a 27-inch monitor at full extension without sagging. One verified buyer wrote: "It's literally an Ergotron LX clone for half the price. Same hinges, same build."
The only difference I can find is the logo. If you're on a budget, this is the arm to get. I'm in the middle of a 90-day side-by-side test with the LX, both mounted with identical 27-inch monitors. Early results: the AmazonBasics is holding its own, but the LX has a slight edge in smoothness.
VIVO Dual Mount
The budget king at ~$89. It holds, it's adjustable, and it's a solid value. But the tilt joint stripped after four months on mine. I've seen the same complaint across buyer reviews: "The tilt joint stripped after 4 months. Now it droops like a sad flower."
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For height adjustment specifically, the gas spring is decent but not great. It holds a 24-inch monitor fine, but I wouldn't trust it with anything heavier. The plastic internals are the weak point.
If you're mounting two 24-inch monitors and you don't move them often, it's fine. If you adjust your monitors daily, spend more. You'll replace this one in a year anyway, and that's the real cost.
NB North Bayou
At ~$40, it's shockingly good for the price. But the gas spring is weak. My 29" ultrawide sagged no matter how much I tightened it. Buyers report the same: "The gas spring is weak. My 29" ultrawide sags no matter how much I tighten it."
The Height Adjustment Problem Nobody Talks About
The clamp always leaves a mark. Whether it's a dent in a butcher block or a gouge in a laminate desk, the C-clamp will damage your surface. Rubber pads help, but grommet mounts are the only real solution.
I've seen a ~$400 desk scarred by a ~$30 arm. The Huanuo's C-clamp cracked a client's desk. The plastic base is too thin. I've seen the damage firsthand. If you're on a budget, buy the NB North Bayou instead. At least it doesn't destroy furniture.
For thick desks, most clamps don't fit. I'm building a new desk for a client with a 3-inch thick top, and I need to find a clamp that actually fits. Most don't. The Ergotron's clamp maxes out around 2.4 inches. The AmazonBasics is the same. If you have a thick desk, you're going grommet mount, and you're doing it right.
Cable Management and Height Adjustment
Cable management is where arms go to die. If the channel can't fit a DisplayPort and a power cable, it's useless. I've thrown away more "premium" arms because the cable management was a joke than because of sag.
Here's the thing: cables affect height adjustment. If the cable is too short, it pulls the arm down. If it's routed wrong, it binds the gas spring. I've seen arms that sagged not because the gas spring died, but because the cable was fighting the movement.
The Ergotron's cable management is decent. The AmazonBasics is the same. The VIVO's is a joke. The NB North Bayou's is barely a channel.
Should You Buy It?
If you want height adjustment that actually holds, the Ergotron LX is the answer. It's expensive, but it's the last arm you'll buy. If you can't stomach ~$249, the AmazonBasics arm is 90% of the way there for ~$99. Either way, stop buying ~$40 arms that sag in six months. I've been there. It's not worth it.
I'm still testing the AmazonBasics against the LX, 90 days of daily use, tracking drift and adjustment smoothness. I'm also testing a new budget arm that claims to hold 20kg. I'll believe it when I see it. And I'm building that desk with the 3-inch top, which means I need to find a clamp that actually fits. Most don't.