A mechanical spring for thick desks, or a 10 kg Constant Force arm with a 10-year warranty

HUANUO FlowLift Pro mechanical-spring monitor arm, no gas vs Ergotron LX Pro monitor arm, Constant Force, up to 10 kg

Is this arm for a standard monitor, or a large or ultrawide screen that needs real headroom?

They hold the screen in two different ways — HUANUO with a mechanical steel spring and no gas, Ergotron with its Constant Force mechanism, spring type unstated — and they fit different desks: up to 90 mm thick for one, 60 mm for the other.

HUANUO FlowLift Pro mechanical-spring monitor arm mounted on a desk edge

HUANUO FlowLift Pro mechanical-spring monitor arm, no gas

7.4/10

Wins 5 of 9

Check price

≈ $50

Ergotron LX Pro monitor arm supporting a large monitor above a desk

Ergotron LX Pro monitor arm, Constant Force, up to 10 kg

8.6/10

Wins 3 of 9

Check price

≈ $199

Point against point

Compared on	FlowLift Pro mechanical-spring monitor arm, no gas	LX Pro monitor arm, Constant Force, up to 10 kg
Spring	Mechanical steel spring, 50,000-cycle TÜV-tested run	Constant Force, spring type and cycle figure not published
Weight range	2–9kg (4.4 to 19.8 lb)	1.8–10kg (4 to 22 lb)
Screen size	13–32 in	Up to 34 in
Desk thickness fit	15–90mm (0.59 to 3.54 in)	10–60mm (0.39 to 2.36 in)
Reach	475mm (18.7 in)	Not published (height up to 46.5cm, 18.3 in, above the desk)
Height travel	Up to 42cm (16.5 in)	33cm (13 in)
Warranty	Not published	10 years
Build	90% steel and aluminum	Not published
Price on Amazon.com	≈ $50 — but about €20 on amazon.de, so check the seller	≈ $199
Listed on amazon.com	Yes	Yes

A tick marks the better answer on that line only. Counting ticks does not decide the page — the two verdicts below do, because these products answer different questions.

Which of the two, for which desk

Buy the FlowLift Pro mechanical-spring monitor arm, no gas

Take the HUANUO for a screen up to 32 in and 9 kg on a desk up to 90 mm thick, with a mechanical spring HUANUO says lost no force over 50,000 cycles and a window that shows when the tension is right.

Buy the LX Pro monitor arm, Constant Force, up to 10 kg

Take the Ergotron for a 34 in or 10 kg screen, or if a 10-year warranty matters more than the upfront price — on a desk no thicker than 60 mm.

What buyers ask us first

Which arm fits my desk?

The HUANUO clamps desks 15 to 90 mm (0.59 to 3.54 in) thick; the Ergotron 10 to 60 mm (0.39 to 2.36 in). Measure the edge first — measuring desk thickness for a clamp shows how.

Which one for an ultrawide screen?

The Ergotron, rated up to 34 in and 10 kg (22 lb); the HUANUO stops at 32 in and 9 kg. A 34 in ultrawide is wider and often heavier than a 32 in screen — see what monitor size fits a typical arm.

Each one, in full

Monitor arms

HUANUO FlowLift Pro mechanical-spring monitor arm, no gas

Mechanical steel spring · 2–9 kg (4.4–19.8 lb) · 13–32" · fits 15–90 mm (0.59–3.54 in) desks

The only monitor arm in this hub that states a purely mechanical spring, with no gas: HUANUO says it measured 0% force loss after 50,000 cycles, with TÜV-tested mechanics, on a 90% steel and aluminum arm for 13–32" screens up to 9 kg (19.8 lb).

Best for: A screen up to 32 in and 9 kg (19.8 lb) on a thick desk, for someone who wants a spring that does not lose force over time.

7.4/10

≈ $50

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Monitor arms

Ergotron LX Pro monitor arm, Constant Force, up to 10 kg

up to 34" · 1.8–10 kg (4–22 lb) · Constant Force motion · 10-year warranty

A monitor arm with Constant Force motion, the highest weight ceiling in this hub at 10 kg (22 lb), 33 cm (13 in) of height adjustment and a 10-year warranty — on a clamp that fits desks only up to 60 mm.

Best for: A heavy screen up to 10 kg (22 lb), repositioned through the day, on a desk no thicker than 60 mm (2.36 in).

8.6/10

≈ $199

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Prices quoted in these summaries are dated readings. The live price is shown next to each product.