Stock stands are freeloaders. They park a plastic foot on your desk, rarely hit eye level, and dare you to share the screen with whoever is standing next to you. A clamp arm floats the panel, hands the surface back, and lets a sit-stand desk change height without you re-aiming a fixed column.
Weigh the monitor without the stand, then pick a job, not a vibe:
- Light 24-27″ under ~15 lb, set once → budget gas spring (North Bayou F80 when it is stocked).
- Everyday single in the LX window (~7-25 lb, typically up to ~34″) → Ergotron LX. Check current price.
- Same everyday weight, but you want UPLIFT checkout + a 15-year warranty story → Range-X ($139).
- Heavy / large past LX (~20-42 lb, ultrawide class up to ~49″) → Ergotron HX. Check current price.
Budget gas spring vs Constant Force is the other fork: gas is fine if you set height once; Constant Force is the “I move this thing all day and I want it to still hold in five years” spring.
1v1s when you are down to two: /compare/ergotron-lx-vs-hx · /compare/ergotron-lx-vs-north-bayou-f80 · /compare/ergotron-lx-vs-uplift-range-x. Desk pair: UPLIFT V3 · /guides/best-standing-desks-under-700.
30-second fork
| Job | Pick | Why |
|---|---|---|
| Everyday Constant Force | Ergotron LX · price varies | Mechanical spring, all-metal, 10-year. Check current price |
| Longest warranty / UPLIFT lane | Range-X · $139 | Gas spring, 15-year UPLIFT, ~26.3″ reach, $139 |
| Quick-swap VESA | Zilker · $99 | Clip on/off; 4.4-11 lb window |
| Multi on one pole | Moontower · $79 | Scales 1→6; narrow per-arm weight band |
| Budget light panel | F80 · $30-$46 | Gas-spring basics for light 24-27″ |
| Heavy / ultrawide | Ergotron HX · price varies | 20-42 lb / ~49″ class. Check current price |
Specs that drive the call
| LX | Range-X | Zilker | F80 | Moontower | HX | |
|---|---|---|---|---|---|---|
| Price | Check current price | $139 · $139 | $99 | $30-$46 | $79 | Check current price |
| Weight | 7-25 lb | 3.75-17.6 lb | 4.4-11 lb | 4.4-19.8 lb | 14.3-17.6 lb / arm | 20-42 lb |
| Typical size | ~34″ | ~32″ | ~27″ | ~30″ | ~27″ | ~49″ |
| Spring | Constant Force | Gas | Gas | Gas | Gas | Constant Force |
| Lift / reach | 13″ / ≤25″ | 13.2″ / 26.3″ | 12.25″ / - | ~15″ / ~21″ | - | 11.5″ / ≤23.6″ |
| Warranty | 10 yr | 15 yr UPLIFT | UPLIFT terms | Seller-dependent | UPLIFT terms | 10 yr |
Weight first, diagonal second. If the naked panel is over the arm’s ceiling, the spring will sag and no amount of hex-key optimism will save you.
Ergotron LX: Everyday Constant Force
Ergotron LX · price varies · check current price on Amazon.
This is the arm people mean when they say “just get an Ergotron.” Mechanical Constant Force spring, not a gas cylinder that softens after a few years of heavy use. All-metal load path, integrated cable channels, clamp or grommet, VESA 75/100, tilt about 70° up / 5° down, 360° rotate. Set height; it stays. 10-year manufacturer warranty.
Limits: 25 lb does not cover every 38-49″ ultrawide. That is HX territory. Polished aluminum shows fingerprints (matte black exists). Clamp wants about 2.4″ of rear desk clearance if the top is flush to a wall.
Buy LX when the panel already fits the everyday window and you move the screen more than once a season. Skip it when the panel is a featherweight set-once job (budget gas spring) or clearly past 25 lb (HX).
UPLIFT Range-X: Warranty lane without LX money
Range-X · $139 · $139 on UPLIFT.
Gas spring, 3.75-17.6 lb, 13.2″ lift, 26.3″ reach (longest in this roundup), tilt +90/-45, clamp 0.75-3.75″ (butcher-block friendly), optional 200×100 adapter, 15-year UPLIFT warranty. On a V3 it can use the threaded frame points for a cleaner mount story than a clamp fighting the back edge.
Pick Range-X when the panel fits the weight window and you want UPLIFT checkout + the long warranty. Pick LX when you want Constant Force and the higher 25 lb ceiling. Deep dive: /compare/ergotron-lx-vs-uplift-range-x.
UPLIFT Zilker: Quick-swap for lighter panels
Zilker · $99 · $99.
Quick-release VESA clip, 4.4-11 lb, about 12.25″ height travel, same wide UPLIFT clamp range. Great when monitors commute between desks or you rotate a spare panel onto the same arm. Check naked weight. Plenty of 27-32″ panels sit over 11 lb and bounce you up to Range-X or LX.
UPLIFT Moontower: One pole, more screens later
Moontower · $79 · $79 single.
Starts single and scales to dual/triple/quad/six on the same pole (dual · $89). Per-arm weight band is tight (14.3-17.6 lb), ~27″ max. Verify each panel before you stack a tower of optimism. Cheaper to add arms on one pole than to buy independent LX units for every screen; you trade some of the independent swing you get from two true singles.
North Bayou F80: Budget gas spring (when stocked)
F80 · $30-$46.
F80 · $30-$46. Light 24-27″ under-~15 lb, set-once lane: clamp, lift, tilt, swivel, rotate. Gas spring, clip-on cables, some plastic trim, short seller-dependent warranty. Fine as a replaceable arm; not a decade Constant Force bet. Check the card for live availability. Never invent a street price.
If F80 is gone and you still want budget-ish gas spring with a real warranty story, Range-X is the grown-up middle. LX vs F80 fence: /compare/ergotron-lx-vs-north-bayou-f80.
Ergotron HX: When LX runs out of weight
Ergotron HX · price varies · check current price on Amazon.
Same Constant Force family, heavier mechanism: 20-42 lb, typical size up to ~49″, 11.5″ lift, reach ≤23.6″ on current sheets, wider VESA patterns on HX Single, 10-year warranty. Floor is 20 lb. A featherweight 24-27″ can sit under the spring window even if the diagonal looks serious.
HX is the capacity fork, not a style upgrade. Under ~20 lb, LX usually does the everyday job. Overlap 20-25 lb: pick LX for the lighter everyday arm, HX if you are already shopping heavy-panel headroom. Deep dive: /compare/ergotron-lx-vs-hx.
Why bother
Eye height on a sit-stand desk, desk surface back, swing/portrait/share without wrestling a stand. Arms are not décor. They are the difference between a floating panel and a plastic foot claiming half your mat.
Buying tips (sparse)
- Weigh without the stand first.
- Measure desk thickness (LX/F80 ~2.4″ clamp story; UPLIFT arms 0.75-3.75″). Glass desks hate standard clamps.
- VESA 75/100 covers almost everything here; confirm the holes exist.
- Reposition all day → Constant Force (LX/HX). Set once → gas spring is fine.
- Under-$150 warranty pick: Range-X ($139). Everyday Constant Force: LX (check current price). Capacity past LX: HX (check current price). More under $150: /guides/best-monitor-arms-under-150.
Frequently asked questions
Safe on every desk?
Solid wood / laminate / composite yes. Glass and hollow cores are the usual problems. Prefer grommet or skip the clamp.
Gas spring vs Constant Force?
Gas can soften over years of heavy use. Constant Force is mechanical. Range-X offsets gas with UPLIFT’s 15-year coverage.
Dual monitors on one LX?
No. Two singles, or Moontower multi. Two singles give more independent aim.
Drill required?
Clamp default; grommet optional.
Curved monitors?
Same VESA story. Weight still rules.
Is the F80 sturdy enough daily?
Yes inside ~19.8 lb when stocked. Shortfall vs LX is long-term gas durability and ceiling, not day-one wiggle on a light 24-27.
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