M56C Ergonomic Office Chair with Ultra-Wide Dual-Section Backrest
Benefits
Benefits
- Ultra-wide dynamic lumbar support for continuous comfort
- Enveloping backrest for full-back support
- Wide headrest for ample neck support
- W-shaped seat cushion for pressure-free seating
Promises
Promises
- 30-Day Worry-Free Trial: Try the chair for 30 days. If it’s not for you, feel free to return it.
- 3-Year Warranty: Enjoy lasting comfort and peace of mind with our 3-year warranty.
- Fast Shipping: Receive your chair in just 5-7 days, in US and CA.
- Satisfaction Guarantee: For any issues, contact support@sihoooffice.com for prompt assistance and guaranteed satisfaction.
Payment methods
Your payment information is processed securely and the price includes regional tax.
How to choose a right ergonomic office chair?
Check out our buying guide for you!
Supports Up to 300 lbs
The M56C features a strong frame and reliable build quality that comfortably supports users up to 300 lbs, ensuring stability and durability for long-term use.
Ultra-Wide Dynamic Lumbar System
Designed to move with you, the flexible lumbar panel offers consistent lower back support during every shift, stretch, or recline—for all-day ergonomic comfort.
20.3" (51.5 cm) Dual-Section Backrest
The extra-wide backrest is made from high-elastic mesh that naturally conforms to your back and shoulders, offering breathable, full-back support for a variety of body types.
W-Shaped Foam Seat Cushion
The precision-cut foam cushion follows a W-shaped design that cradles your hips and thighs, distributing pressure evenly for soft, balanced seating throughout your workday.
Adjustable Wide Headrest
The spacious, curved headrest supports your head and neck—even when you lean to the side—and adjusts up/down and tilts to match your sitting posture.
Height-Adjustable PU Armrests
With wider, softer PU padding, the armrests offer a skin-friendly surface and simple up/down adjustment to help reduce shoulder and wrist strain.
125° Recline for Relaxation
Lean back and unwind between meetings or tasks with a smooth reclining range up to 125°, offering comfort when you need to reset and refocus.
Premium Materials, Lab-Tested Reliability
Constructed from breathable mesh, durable steel/nylon components, and soft-touch foam, the M56C is rigorously tested to meet lasting ergonomic performance standards.
BIFMA & SGS Certified
Backed by global safety certifications, the M56C delivers professional-grade support with peace of mind for both office and home work setups.
Quick & Easy Assembly
Everything you need is in the box—including tools and clear instructions—so setup is fast and frustration-free.
What makes the M56C different from other ergonomic chairs?
The M56C offers an ultra-wide dynamic lumbar support system that flexes with your movements for continuous lower back comfort. It combines a spacious dual-section backrest and a W-shaped foam seat cushion that evenly distributes pressure. The chair also features a wide adjustable headrest and height-adjustable armrests for essential support tailored to your needs.
How does the lumbar support in the M56C work?
The M56C’s lumbar system uses a flexible elastic plate that moves with your body, providing stable and consistent support no matter how you twist, lean, or recline. This keeps your lower back relieved throughout the day.
Can the M56C fit users of different heights and sizes?
Yes. The M56C’s design suits users of various body types, providing full-back support with its wide backrest and adaptive lumbar system. The height-adjustable headrest and armrests help customize the fit for comfort, supporting a broad range of users.
What adjustment options does the headrest offer?
The M56C’s headrest is spacious and adjustable—it moves up and down and can tilt to fit your head and neck position, reducing strain during long hours of work or video calls.
How do the armrests on the M56C improve comfort?
The M56C features soft, wide PU-padded armrests that adjust up and down only. This simple vertical adjustment helps you find the right height to reduce shoulder and wrist fatigue, providing reliable support while you work.
Is the M56C easy to assemble?
Yes. The M56C comes with all the necessary parts and clear instructions for quick and hassle-free assembly. You’ll be ready to work comfortably in no time.
What is the weight capacity of the M56C?
The M56C supports users up to 300 lbs, ensuring strength and durability for a wide range of body types.
Is the M56C designed for long hours of sitting?
Definitely. With its breathable mesh back, dynamic lumbar support, pressure-relieving W-shaped seat cushion, and ergonomic adjustments, the M56C is built to keep you comfortable and supported during extended work sessions.
Sitting all day shouldn't leave you feeling sore and worn out. If your lower back aches after hours at your desk or your seat feels flat and unforgiving by mid-afternoon, it’s time for a better solution. The Sihoo M56C is designed to relieve daily pressure with dynamic lumbar support and a soft, contoured seat—so you can sit comfortably, stay focused, and get through your workday without the strain.
Headrest
Lumbar Support
Armrests
Comfort Seating


Spacious Headrest
Neck strain is a common issue when your chair doesn't support your posture. The M56C’s wide, adjustable headrest gives your neck the support it needs, helping prevent stiffness and pain from looking at screens all day.


Ultra-Wide Dynamic Lumbar Support
Tired of lower back pain after a long day at your desk? The M56C’s ultra-wide dynamic lumbar support moves with your body to keep your spine properly aligned. Whether you're leaning forward or reclining, it offers real-time support that helps reduce pressure and discomfort.


Adjustable Armrests
Tired of armrests that don’t match your setup? The M56C’s adjustable armrests move up and down. They support your arms in any sitting position, reducing shoulder tension and wrist fatigue—ideal for typing, writing, or gaming.


Full-Back Support Meets Pressure-Free Seating
Tired of backaches and sore hips from sitting too long? The M56C features an ultra-wide, dual-section backrest that hugs your entire back—from lower spine to shoulders—for balanced support all day. Paired with a soft, W-shaped seat cushion that follows the natural curves of your hips and thighs, it helps reduce pressure points and keeps you comfortable, even during long work sessions.
Adjustable Comfort

Adaptive Lumbar System
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Support That Moves With You
Whether you’re leaning forward or reclining back, the dynamic lumbar support adjusts in real time to keep your lower back fully supported.
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Comfort for Every Body
No matter your size or weight, the lumbar support flexes and rebounds to match your body’s shape—giving you tailored support that never quits.
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Engineered for Real Support
A side view of the dual-layer lumbar system reveals its built-in flexibility and firm core—designed to cradle your spine where it matters most.
Compare & Pick the Right Chair
What's the difference between M56B, M56C and C300?

M56C

M56B

C300
Recline angle
110° - 125°
110° - 125°
110° - 120° - 130°
Armrests
Up and down adjustable
3D adjustable
4D adjustable
Mesh Material
High elastic mesh back + cotton cushion
Full chair with Dragon-Scale mesh
Mid-grade polyester mesh
Price
$209.99
$229.99
$289.99