SIHOO Doro C300 Pro Ergonomic Chair
The Doro C300 Pro upgrades SIHOO's popular ergonomic chair with 6D armrests, seat depth adjustment, and an adjustable backrest — making the sub-$500 Aeron alternative argument harder to dismiss.
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What we like
- 6D armrests adjust in five directions and follow the recline
- Seat depth slider accommodates taller users and longer femurs
- Backrest height adjusts 2.36 inches across four positions
- Dynamic lumbar support tracks lower back as you shift
- 330 lb weight capacity with weight-sensing tilt mechanism
Could be better
- Mesh is firmer than premium chairs in this segment
- Assembly instructions are sparse and translation is rough
- No forward seat tilt for active sitting postures
Full Review
The Doro C300 Pro is what the base C300 should have been. SIHOO took the criticisms of the original — fixed armrests, no seat depth, limited backrest range — and addressed them without doubling the price. At $399, it sits in the middle of the “sub-$500 Aeron alternative” tier alongside the Branch Verve and Hinomi H1 Pro.
What the Pro Adds Over the Base C300
The headline upgrade is the 6D armrests. They move up, down, forward, back, side-to-side, and pivot inward — and they follow the backrest when you recline, which the base model’s 3D arms don’t do. For typing posture this matters more than spec sheets suggest. Seat depth adjustment is the second meaningful change: a slider extends the cushion roughly two inches, so taller users with longer femurs aren’t perched on the front edge.
Lumbar and Recline
The dynamic lumbar support is the same system as the base C300 — a curved pad that tracks your spine as you shift in the seat. It works well for hours of focused work but isn’t as aggressive as the Hinomi H1 Pro’s adjustable lumbar block. Recline locks at 105°, 120°, and 135° with a weight-sensing tilt that auto-adjusts resistance based on your weight, so you don’t fight the chair when leaning back.
Build and Materials
The mesh is firmer than the Branch Verve’s woven seat and noticeably less plush than anything from Herman Miller or Steelcase. That’s the trade-off at this price. Frame quality is solid, the gas lift is SGS-certified, and BIFMA compliance means it’ll survive a real workday. Assembly takes 30-40 minutes and the instructions are SIHOO’s usual rough translation — workable, not polished.
Vs. the Competition at $400
Against the Branch Verve ($499), the Doro C300 Pro gives you 6D armrests at a lower price but loses on overall material feel. Against the Hinomi H1 Pro ($549+), Hinomi wins on lumbar adjustability and headrest design, but costs more. Against the base SIHOO C300 ($299), the Pro’s $100 premium is justified if you’re over 6’0” or want armrests that follow your recline.
Who Should Buy This
Buy the Doro C300 Pro if you want the most adjustable ergonomic chair under $400 and you specifically need 6D armrests or seat depth adjustment. If you’re under 5’10” and the base C300 fits, save the $100. If you want premium materials and a softer mesh feel, stretch to the Branch Verve or wait for an Aeron sale.
