For most people the Sihoo M57 is the right buy: full mesh, lumbar adjustable in height and depth, 3D arms, a headrest and a 150 kg rating. Step up to the M57 Pro if you want 4D arms, adaptive lumbar and a deeper recline. Choose the DORO-C300 Pro V2 if you sit six hours or more a day and want a chair whose lumbar, recline tension and seat move with you rather than waiting to be adjusted.
- M57: full mesh, dual-adjust lumbar, 3D arms, 126° lockable recline, headrest, 150 kg, seat height 42–52 cm (roughly 155–185 cm).
- M57 Pro: full mesh with elastic foam seat cushioning, adaptive lumbar, 4D arms, 134° recline, double-joint 3D headrest, BIFMA tested.
- DORO-C300 Pro V2: DynaCore full-body support, self-adaptive lumbar 2.0 that slides with your centre of gravity, 8D arms, 135° recline with locks at 105°, 120° and 135°, auto-calibrating tension for 40–100 kg, 4 cm seat slide, 150 kg, fits 150–190 cm.
- All three carry Sihoo's 3-year warranty handled through Aussie Chair, an authorised Sihoo dealer, and all three are on the floor in Sydney and Melbourne.
Last updated October 2026. Specifications checked October 2026; current pricing is on each product page.
Sihoo M57 vs M57 Pro vs DORO-C300 Pro V2 at a glance
| Sihoo M57 | Sihoo M57 Pro | Sihoo DORO-C300 Pro V2 | |
|---|---|---|---|
| Seat and back | Full mesh, waterfall front edge | Full mesh with built-in elastic foam seat cushioning | Full mesh; SyncroFlex backrest glides with you as you recline |
| Lumbar support | Manual: height and depth adjustable | Adaptive: flexes with your posture | Self-Adaptive 2.0 with Body Movement Tracking: pad slides down with your centre of gravity on recline |
| Armrests | 3D (height, forward/back, 34° swivel) | 4D | 8D bionic (height, forward/back, 360° rotation, tilt) |
| Recline | Lockable to 126° | To 134° | To 135°, locks at 105°, 120°, 135°; tension auto-calibrates for 40–100 kg |
| Headrest | 8 cm height travel, 45° rotation | Double-joint 3D | Ultra-wide 3D, 28% more area than Gen 1 |
| Seat depth adjustment | No | No | Yes, 4 cm slide |
| Weight rating | 150 kg, BIFMA and SGS tested, 907 kg static test | BIFMA tested; rating on product page | 150 kg, BIFMA, SGS and TÜV certified |
| Height fit | Seat 42–52 cm, roughly 155–185 cm | Similar to M57; four backrest heights | 150–190 cm |
| Colours | Black, Grey | Black, Grey | Black, Grey; with or without footrest |
| Warranty | 3 years, handled through Aussie Chair in Australia | ||
What does the extra money buy at each step?
From the M57 to the M57 Pro, the step up buys three things you touch every day: the armrests go from 3D to 4D so the pads rotate inward to support a keyboard posture; the lumbar becomes adaptive, flexing as you shift instead of holding one position; and the recline opens from 126° to 134°. The seat also gains built-in elastic foam cushioning, which makes the Pro a better fit for people who find bare mesh firm on the sit bones. The headrest upgrades to a double-joint 3D unit.
From the M57 Pro to the DORO-C300 Pro V2, the next step buys a different class of mechanism. The lumbar pad does not just flex: it tracks your centre of gravity and slides down as you recline, closing the gap that opens at the sacrum on a conventional chair. The recline tension sets itself to your weight between 40 and 100 kg, so two people can share the chair without touching a dial. The seat slides 4 cm for thigh fit. The arms are 8D, with 360° rotation and tilt. And the whole backrest glides with you as you lean back rather than pivoting at one point. Sihoo calls the package DynaCore; in practice it means the chair keeps contact with your back through every posture change in an eight-hour day.
Fixed, adaptive or tracking lumbar: which do you actually need?
If you sit upright, adjust a chair once and leave it, the M57's manual lumbar is the best kind: you put firm support exactly where your lower back wants it and it stays there. If you shift posture often — leaning in to read, back to think, sideways to a second screen — an adaptive lumbar (M57 Pro) keeps contact without you reaching for a dial. If you also recline a lot, or your lower back goes quiet by mid-afternoon in a fixed-pad chair, the V2's tracking lumbar is the one that follows you down into the recline and back up. The honest test: notice how many times a day you readjust your current chair's lumbar. Zero means the M57 is enough; several means the V2 will feel like a different experience.
Who fits which chair?
The M57's seat height of 42–52 cm suits people from roughly 155 to 185 cm, and the M57 Pro is similar with four backrest height positions. Neither has seat-depth adjustment, so if you are under about 165 cm or have shorter legs, check that the seat edge sits two to three fingers behind your knee with your back against the lumbar — if it does not, the V2's 4 cm seat slide is the fix, and it is the only one of the three that has it. The V2 fits 150–190 cm. On weight, the M57 and V2 are both rated to 150 kg with BIFMA testing; the Pro's rating is on its product page. All three use five-star bases and lockable recline; the V2 adds TÜV certification. For anyone over 190 cm or over 150 kg, our big and tall office chairs page covers the LiberNovo Maxis and Aeron Size C instead.
Is the M57 Pro worth the step up from the M57?
Yes, if any of these describe you: your forearms rest on the armrests while you type (4D arms), you shift posture a lot (adaptive lumbar), you recline to read or take calls (134° versus 126°), or you have found mesh seats too firm (the Pro's cushioning). No, if you want the coolest, firmest seat and set-and-forget support — the M57's manual lumbar is more precise for an upright sitter.
Is the DORO-C300 Pro V2 worth the jump from an M57?
For a six-to-ten-hour desk day, yes. The three things the V2 does that neither M-series chair can — track the lumbar through recline, calibrate tension to your weight, and slide the seat — are exactly the three things that matter when you are in the chair all day rather than for a couple of hours. For a two-to-four-hour day, a shared family desk where the budget is tight, or a second chair, the M57 or M57 Pro gets you most of the ergonomic benefit with a much simpler mechanism. The footrest version only makes sense if you nap or game reclined; for work, skip it.
DORO-C300 Pro Gen 1 or V2?
We still stock the first-generation DORO-C300 Pro, with or without footrest. It has the self-adaptive lumbar with Body Movement Tracking, 6D arms, an adjustable headrest and 42.7–45.1 cm of seat depth, rated to 150 kg for 152–190 cm. The V2 adds the sliding lumbar that follows your centre of gravity, 8D arms, the SyncroFlex gliding backrest, auto-calibrating tension and a 28% larger headrest. If the budget is tight, the Gen 1 is still an excellent chair; if you can stretch, the V2's auto-calibrating tension and gliding back are the upgrades you feel on the first recline.
So which Sihoo should you buy?
- Two to four hours a day, upright, set-and-forget: M57.
- You type with forearms on the arms, shift posture often, or find mesh firm: M57 Pro.
- Six hours or more a day, you recline, or your lower back fades by mid-afternoon: DORO-C300 Pro V2.
- Under 165 cm or shorter legs: V2 (the only one with seat-depth adjustment), or sit-test the M57 first.
- Shared chair between two people of different weights: V2, for the auto-calibrating tension.
- Budget is tight but you want tracking lumbar: DORO-C300 Pro Gen 1.
- Gaming in long reclined sessions: the V2 with footrest, or the XALLKING X5 Pro.
FAQ
What is the difference between the Sihoo M57 and M57 Pro?
The M57 Pro upgrades the armrests from 3D to 4D, replaces the manual lumbar with an adaptive one that flexes with your posture, deepens the recline from 126° to 134°, fits a double-joint 3D headrest and adds elastic foam cushioning to the mesh seat. Current pricing is on each product page.
Is the Sihoo DORO-C300 Pro V2 worth it over the M57?
For a full working day, yes: the V2's lumbar tracks your centre of gravity through recline, its tension calibrates itself to your weight, and its seat slides 4 cm, none of which the M57 does. For a few hours a day, the M57 delivers most of the ergonomic benefit and is the value pick.
Which Sihoo chair has seat-depth adjustment?
Of these three, only the DORO-C300 Pro V2, with a 4 cm slide. The M57 and M57 Pro have fixed seat depth. Elsewhere in the Sihoo range the V1, S100, DORO-C300 Pro Gen 1 and DORO-C500 also adjust seat depth.
What weight can the Sihoo M57 and DORO-C300 Pro V2 hold?
Both are rated to 150 kg by Sihoo. The M57 has passed BIFMA and SGS testing including a 907 kg static pressure test; the V2 is BIFMA, SGS and TÜV certified. The M57 Pro has passed BIFMA durability testing; its weight rating is listed on its product page.
What warranty do Sihoo chairs have in Australia?
Three years, handled through Aussie Chair as an official authorised Sihoo dealer. Claims are managed locally with proof of purchase and a photo of the fault.
Can I try all three before buying?
Yes. The M57, M57 Pro and DORO-C300 Pro V2 are on the floor side by side at our Sydney showroom (11/46-50 Wellington Rd, South Granville NSW 2142) and our Melbourne showroom (Shop 1A/280 Whitehorse Rd, Nunawading VIC 3131). Delivery is free Australia-wide, and we ship to New Zealand.
Where to try the Sihoo range
All three chairs, plus the DORO-S300 and DORO-C500, are on the floor in Sydney (South Granville) and Melbourne (Nunawading); book through our showrooms page and we will set each one to your height and desk. Browse the full Sihoo range, or compare them against Herman Miller, LiberNovo and UE in our ergonomic chair range. For what the testing standards behind the weight ratings actually mean, see BIFMA.
