When Geeky Gadgets reviewed the Sihoo Doro C300 Pro in January 2025, the chair already offered 6D armrests, an adjustable-depth seat, and weight-responsive reclining. Those were useful features then, and they make a good starting point for understanding what Sihoo has changed on the Doro C300 Pro V2.
The V2 brings 8D armrests, a gliding backrest mechanism, and an updated lumbar unit. Some of the changes are aimed at a fairly specific problem: supporting the arms and lower back when someone moves away from an upright typing position.
From 6D to 8D armrests
The previous C300 Pro already had coordinated armrests that followed the chair during recline. On the V2, Sihoo has expanded the adjustment range and introduced a rear section that tilts upwards.
That raised section is intended to support the elbows when using a handheld gaming console. Holding a device close to the body puts the forearms in a different position from typing at a desk, where the hands reach forward. The V2 also allows the armrests to rotate, move forwards and backwards, and swing aside when the user wants to pull closer to the desk.
The latter adjustment could be useful at a crowded workstation, although clearance will depend on the desk itself. The more unusual addition is the upward-tilting rear pad, which gives the V2 a distinct armrest feature that the earlier Pro lacked.
A backrest designed to glide during recline
The other substantial change is behind the seat. Sihoo calls its updated backrest mechanism SyncroFlex. It uses two tracks and two springs to allow the backrest to glide as the chair reclines, with the aim of maintaining contact as the angle between the upper body and seat changes.
Sihoo groups that movement with the headrest, armrests, and lumbar support under the name DynaCore. The idea is coordinated support, although the two names refer to different things: SyncroFlex is the backrest mechanism; DynaCore describes how several parts of the chair are designed to move together.
For anyone comparing the generations, this is more relevant than the recline angle alone. The question is not just how far the chair goes back, but whether the lower-back support stays in place along the way. That is what Sihoo says the new mechanism is intended to address.
Domino 2.0 offers more lumbar adjustment
The V2 also uses Sihoo’s Domino Sacral-Lumbar Support 2.0. The support area extends across the lower back towards the sacrum, while a pressure-relief spring gives the unit some movement as the user shifts position.
There is a manual element, too. The lumbar assembly can be positioned vertically, and three support settings allow the user to choose the amount and position of contact. In other words, the mechanism is designed to respond to movement after it has been set up; it does not choose a preferred lumbar setting for the user.
Seat dimensions and the features carried over
The V2 retains the Pro’s adjustable seat: it measures 52 cm across and slides between 43 and 47 cm in depth. Sihoo recommends a user height of roughly 150 to 190 cm, although seat depth still needs to match the person using it.
The V2 reclines to 105, 120, and 135 degrees and retains weight-responsive resistance. An adjustable 3D headrest and Cloud Mesh 2.0 upholstery round out the main features. Sihoo also sells a footrest version; the footrest is not included with every chair.
Who should consider the V2?
For someone moving between typing, handheld gaming, and reclining, the new armrest positions and gliding backrest are worth examining. Those adjustments may matter less to a desk user who stays mostly upright.
Existing C300 Pro owners already have a sliding seat and weight-responsive recline. The V2 upgrade rests on its armrests and redesigned support system, which are best judged in person rather than by adjustment counts.
The C300 Pro V2 carries a three-year warranty against manufacturing defects. Configurations, pricing and return terms depend on the region; full details are available from Sihoo’s official store.
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