# Sihoo office chairs compared: M57, M18 and M59AS

Source: https://chairandposture.co.uk/best/sihoo-office-chairs-compared
Publisher: Chair and Posture. Picks are based on what the Amazon listings state, not on hands-on testing. Method: https://chairandposture.co.uk/how-we-pick

Sihoo sells several mesh office chairs on amazon.co.uk that look alike in photos but differ in the parts that decide comfort. The M57 is the all-mesh classic with an S-shaped back. The M18 swaps the mesh seat for a padded W-shaped cushion. The M59AS splits the backrest in two and adds a self-adjusting lumbar pillow and flip-up arms. All three state the same 150 kg load rating, so the choice comes down to lumbar design, armrest movement, seat type and recline. This guide puts the three side by side on exactly those points, using only what each listing states. The Doro and C300 models that people also search for were not part of the collection we compared, so they are not covered here.

## Products

### 1. SIHOO M57 Ergonomic Mesh Office Chair, Lumbar Support, 330 lb

Back design: S-shaped mesh; Lumbar: Built into back; Tilt: 110°, 116°, 126°; Armrests: 3D; Max load: 150 kg

A popular all-mesh chair with an S-shaped back, adjustable headrest, 3D arms and three recline positions. It suits anyone who wants the Aeron's all-mesh feel at a much lower tier.

In its favour:
- Both seat and back are polyester mesh, the closest thing here to the Aeron's all-mesh layout.
- The 3D armrests have 5 height positions, slide forward and back, and rotate.
- Sihoo states a BIFMA and SGS certified gas lift, a 150 kg rating and a 3-year parts warranty.

Good to know:
- The lumbar is shaped into the back rather than separately adjustable.
- Seat height travel is about 10 cm and there is no seat depth slide.

### 2. SIHOO M59AS Ergonomic Office Chair, Dual Backrest, Adaptive Lumbar Support

Back design: Dual split back; Lumbar: Adaptive pillow; Tilt: Rocking; Armrests: 3D linked, flip-up; Max load: 150 kg

A mesh chair with a two-piece backrest, a lumbar pillow that adjusts itself as you move and flip-up 3D arms. It suits people curious about split-back designs on a tighter budget.

In its favour:
- The two separate back halves are designed to follow the curve of your back as you move.
- The armrests are linked to the back so they keep supporting your arms as you recline, and flip up 80°.
- Sihoo states BIFMA and SGS certification and a 150 kg load rating.

Good to know:
- There is no manual lumbar or seat depth adjustment listed.
- The listing does not state a recline angle or warranty length.

### 3. SIHOO M18 Ergonomic Office Chair, Adjustable Lumbar Support, 330 lb, Black

Seat depth: Not stated; Lumbar: Adjustable back support; Armrests: Height adjustable; Recline: 4 positions; Max load: 150 kg

A long-running Sihoo design with a mesh back, adjustable back support and headrest, a waterfall-edge seat and a 150 kg rating. It suits people who want a simple, proven layout.

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.

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