Start with the C300 Pro V2 if you want a separate headrest, more arm-pad positioning, and a choice of lumbar support levels. Consider the S300 if adjustable recline tension and its integrated upper-back support are the features you want to pay for. A higher price doesn't establish better comfort for your body.
This comparison uses Sihoo's US specifications and adjustment instructions, checked October 1, 2026. WorkstationSetup hasn't tested either chair hands-on. These are buying reasons to investigate, not measured comfort or durability results.
Swipe the table to compare the controls.
Choose the V2 for more positioning options
Its backrest has seven height settings across a stated 3.2-inch range. The separate headrest and adjustable lumbar height let you position those parts independently. Sihoo also shows the arms swinging aside to approach a desk. That's useful to check if your current arm pads block your keyboard position; it isn't a promise that the whole chair will fit under your desk.
Skip the upgrade if the base C300 Pro's seat slider and 6D arms already give you the positions you need. More movement adds options, not a reason to replace a chair that already fits.
Choose the S300 for its recline controls
The S300's recline mechanism and tension adjustment are its distinct buying case. Its dual lumbar pads have an angle control, while head support moves with the upper back rather than on a separate headrest. Check the adjustment instructions if you prefer setting resistance yourself or want to understand how that linked support moves.
Skip it if you're paying mainly for a longer warranty: both list three years. The S300 has 6D arms, so its flagship position also doesn't give it the V2's 8D armrest system.
Check the version and return terms in your cart
C300 Pro and C300 Pro V2 are separate products. Each has Standard and Footrest options. The V2 card here links to Black Standard; it doesn't include a footrest. The S300 card links to Black. Check the selected version, color and current total at Sihoo before comparing prices. A footrest option changes the purchase, not the name of the base Pro into a V2.
Sihoo advertises 30-day returns, but its policy's eligibility wording requires an unused chair with original packaging while the FAQ also discusses returns after normal use. Don't assume an assembled-chair comfort trial is free. Get approval and written clarification on eligibility, return shipping and deductions before relying on a return. The three-year warranty covers manufacturing defects under the policy, not a promise of fit.
Official US sources: C300 Pro V2 specifications and drawing, S300 specifications, S300 adjustment manual, base C300 Pro, warranty policy, returns policy.
