Product · SIHOO
Sihoo M18: adjustable back support, 150 kg
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The Sihoo M18 is one of the longest-running designs in Sihoo's range and it keeps things straightforward. Five adjustments cover back support, headrest, seat height, recline and armrest height. A mesh back keeps you cool, and an upholstered seat with a waterfall front edge eases pressure on the legs. It suits people who want a reliable, uncomplicated chair rated to 150 kg.
- Seat depth
- Not stated
- Lumbar
- Adjustable back support
- Armrests
- Height adjustable
- Recline
- 4 positions
- Max load
- 150 kg
In its favour
- Five adjustment settings cover back support, headrest, seat height, recline and armrest height.
- The seat has a W-shaped cushion and a waterfall front edge, which Sihoo says keeps pressure off the legs.
- Sihoo states BIFMA testing, a 150 kg rating and a 3-year parts warranty.
Good to know
- The seat does not slide, so shorter or taller users cannot fine-tune seat depth.
- The armrests only move up and down, with no forward, back or pivot movement.
Our take
The five adjustments
Back support adjusts to sit in the lower back, and the headrest moves to support the neck. Seat height uses a gas lift, the backrest reclines with four positions according to Amazon, and the armrests move up and down. The item highlight on Amazon calls them 2D, but the bullets describe height adjustment only, so do not expect forward or sideways movement.
That short list is the M18's strength and weakness: there is little to learn, but also less fine-tuning than newer chairs.
Seat design
The seat cushion uses high-density sponge in a W shape that is meant to centre you on the chair. A waterfall front edge rolls down rather than ending in a hard lip, which reduces pressure behind the knees during long sits. Amazon gives a seat depth of about 50 cm and a backrest width of about 51 cm. There is no seat slide.
Strength, assembly and warranty
Sihoo says the chair has passed BIFMA testing and a 1,136 kg static pressure test, with a user rating of 150 kg. Assembly takes eight steps. The chair weighs about 17 kg and stands about 127 cm tall. Sihoo provides a 3-year warranty with free replacement parts and accepts returns within 30 days for faults or quality issues.
When to choose something else
If you want arms that slide or pivot, the Songmics ergonomic chair offers 4D arms with a 5-year warranty at the same load rating. If your thighs are notably long or short, the Flexispot ErgoX gives a 6 cm seat slide and adaptive lumbar. The Hbada P5 adds a sprung seat and a footrest for resting. The M18 makes sense when simplicity and a proven design come first.
Verdict
Buy the Sihoo M18 if you want a familiar, easy chair with a mesh back, headrest and a 150 kg rating. For more arm adjustment and longer cover, the Songmics is a better pick, and if you need seat depth control, the Flexispot ErgoX is the step up.
Compared with alternatives in: Best office chairs under £300
Amazon listing title: SIHOO M18 Ergonomic Office Chair, Adjustable Lumbar Support, 330 lb, Black