SIHOO Doro C300 Ultra V2 vs SIHOO Doro S300: Which Should You Buy?

Key difference: The C300 Ultra V2 lists $320 lower, but the Doro S300 has automatic lumbar support.

What follows compares the C300 Ultra V2 and Doro S300 on SIHOO's own specifications and regular US list prices, not on a Chairpedia test.

Why compare them

Why put the SIHOO Doro C300 Ultra V2 next to the SIHOO Doro S300? The Doro S300 carries the highest list price in SIHOO's Doro line and the C300 Ultra V2 is the top model of the C300 series; the two are built around different backrest and lumbar designs, so the question is which approach suits you.

Specs side by side

Strengths and weaknesses

SIHOO Doro C300 Ultra V2

Strengths

• Lower list price: from $679.99 against $999.99 for the Doro S300.
• 8D armrests, against 6D armrests on the Doro S300.
• Lumbar you set by hand ("Domino Sacral-Lumbar Support 2.0: moves up or down, 3 support levels"), where the Doro S300's works on its own.
• Deeper recline: up to 135° against 130° on the Doro S300.
• A Footrest Version is sold; none is listed for the Doro S300.

Good to know

• Plan a minute to set the lumbar by hand ("Domino Sacral-Lumbar Support 2.0: moves up or down, 3 support levels"); the Doro S300's moves on its own.

SIHOO Doro S300

Strengths

• Automatic lumbar support ("Dual dynamic lumbar support; angle 90°-105° fine-tuned with the gas lift"), where the C300 Ultra V2's is set by hand.

Good to know

• Compare the list prices first: it starts at $999.99, against $679.99 for the C300 Ultra V2.
• If you like to fine-tune the arm pads, note these are 6D armrests, against 8D on the C300 Ultra V2.
• If you like to fix the lumbar in one spot, note no manual setting is listed for the Doro S300, unlike the C300 Ultra V2.
• If you lean far back, note it reclines up to 130°, against 135° on the C300 Ultra V2.
• If you want a built-in footrest, look at the C300 Ultra V2; no footrest version is listed for the Doro S300.

How they differ

Price. At regular US list prices the SIHOO Doro C300 Ultra V2 is $679.99–$689.99 and the SIHOO Doro S300 is $999.99. The C300 Ultra V2 lists $320 below the Doro S300, before any store sale. Price options: the C300 Ultra V2 — Footrest Version (Black $679.99, White $689.99; the only version on the US store); the Doro S300 — $999.99 (Black and White).

Lumbar support. The SIHOO Doro C300 Ultra V2 lists “Domino Sacral-Lumbar Support 2.0: moves up or down, 3 support levels”, the SIHOO Doro S300 “Dual dynamic lumbar support; angle 90°-105° fine-tuned with the gas lift”. The Doro S300's lumbar moves on its own as you shift, while the C300 Ultra V2's is positioned by hand.

Armrests. The SIHOO Doro C300 Ultra V2 lists “8D Bionic Armrests (up, down, forward, back, rotate, or tilt)”, the SIHOO Doro S300 “6D coordinated armrests (up and down, left and right, front and back, inward and outward, with tilt-lock of armrests, and synchronized recline)”. With 8D armrests the C300 Ultra V2 lets you set the pads in more ways than the Doro S300.

Recline. The SIHOO Doro C300 Ultra V2 lists “Up to 135°; positions at 105°, 120° and 135°”, the SIHOO Doro S300 “Up to 130°; positions at 100°, 110° and 130°”. The C300 Ultra V2 leans back further than the Doro S300.

Footrest. SIHOO sells a Footrest Version of the C300 Ultra V2; no such version is listed for the Doro S300.

Seat size. Seat height: the SIHOO Doro C300 Ultra V2 lists “≈18.7–21.9 in (47.5–55.5 cm)”, the SIHOO Doro S300 “18.50–21.85 in (47–55.5 cm)”. Seat width: the SIHOO Doro C300 Ultra V2 lists “20.5 in (≈52 cm)”, the SIHOO Doro S300 “20.28 in (51.5 cm)”. Seat depth: the SIHOO Doro C300 Ultra V2 lists “16.9–18.5 in (≈43–47 cm)”, the SIHOO Doro S300 “15.75–18.50 in (40–47 cm)”.

Other details. For the C300 Ultra V2 and Doro S300, the table above gives the headrest and chair weight in each brand's own wording.

Same on both. The C300 Ultra V2 and Doro S300 list the same warranty (3 years) and maximum load (330 lb, ≈150 kg).

Who should buy which

• Pick the C300 Ultra V2 over the Doro S300 if you want the lower price — the C300 Ultra V2 lists $320 below the Doro S300.
• Pick the C300 Ultra V2 over the Doro S300 if you want 8D armrests rather than 6D.
• Pick the C300 Ultra V2 over the Doro S300 if you want a lumbar position you set yourself and that stays put.
• Pick the Doro S300 over the C300 Ultra V2 if you want lumbar support that adjusts itself as you move, with nothing to set.

Sources

• SIHOO Doro C300 Ultra V2 (compared here with the Doro S300): Doro C300 Ultra V2 Zero‑Gravity Full‑Body Adaptive Ergonomic Chair – UK Sihoo official Shop; Sihoo Doro C300 Ultra V2 | Ergonomic Office Chair – Official US Sihoo Store, checked 2026-10-13; US list price from SIHOO US Official Store, checked 2026-10-13.
• SIHOO Doro S300 (compared here with the C300 Ultra V2): Doro S300 Ergonomic Chair – UK Sihoo official Shop; Sihoo Doro S300 Zero Gravity Ergonomic Office Chair – Official US Sihoo Store, checked 2026-09-29; US list price from SIHOO US Official Store, checked 2026-10-07.
• Figures marked ≈ for the C300 Ultra V2 and Doro S300 are Chairpedia's unit conversions, not brand figures.