Sihoo S100 Ergonomic Office Chair

The Sihoo S100 is a full-mesh task chair built around a split backrest: a separate upper panel for the shoulders and upper spine, and two independent lumbar wings below it that move with you instead of sitting there as one fixed pad. If soft foam chairs have felt vague to you by the middle of a long afternoon, this is the opposite approach.

The split back

The upper panel carries the shoulders while the paired lumbar sections follow the lower back and the sides of the waist separately. Because the two halves are not tied to each other, shifting your posture does not pull support away from one side. Sihoo calls this dual dynamic lumbar support. In practice it means the chair keeps contact when you turn to a second monitor or lean on one elbow.

Fit and adjustment

The seat pan slides through a depth range of 38.5 to 43.5 cm, which is the adjustment that matters most for thigh support. Set it so two or three fingers fit between the front edge of the pan and the back of your knee. The backrest raises and lowers between 46 and 54 cm, so the lumbar wings can be brought to your waist height rather than a generic one. The armrests are 4D: roughly 7 cm of height, 3 cm forward and back, and 72 degrees of pad rotation. The headrest adjusts as well, and the recline opens to 135 degrees for reading or a break.

Mesh, seat and frame

Back and seat are both mesh, so there is no foam layer holding heat against you through a warm afternoon. The front of the seat is cut in a waterfall shape to keep pressure off the underside of the thigh. The chair sits on a five-star base with castors, and comes in the light colourway shown.

• Weight rating: 150 kg, per Sihoo's Australian listing
• Maximum hip width: 51 cm
• Overall size: 67 cm wide, 70 cm deep, 111 to 126 cm tall
• Chair weight: about 22.3 kg
• Suggested sitter height: roughly 150 to 190 cm, per Sihoo's own guidance
• Certification: BIFMA and SGS tested

Before you buy

Sihoo sits below the Herman Miller and LiberNovo lines we carry, and it is honest to say so: this is a well-specified chair for the money rather than a lifetime purchase. The best way to judge any chair is to sit in it, and our showrooms are open for that, in Alexandria, South Granville and Nunawading — message us first to check which Sihoo models are on the floor, since not every model is out at every showroom. We deliver across Australia and New Zealand. Warranty here is one year upwards. Ask us and we will confirm the current term before you order, or browse the rest of the Sihoo range.