














SIHOO B300 Pro Ergonomic Office Chair Without Footrest, 4D Lumbar Support
US$485.98
Estimated delivery: 2–7 business days ✓ Free shipping — over $200Description
Product Details Color:Grey Pattern:Solid Size:Pack of 1 Item Dimensions:28.34 x 28.93 x 51.18 inches Item Weight:40.8 pounds Maximum Weight Recommendation:300 pounds Included Components:Arm...
Delivery & Returns
Free shipping over $200
Orders of $200 or more ship free. No code needed.
Reviews
More options
Product Details
- Color:Grey
- Pattern:Solid
- Size:Pack of 1
- Item Dimensions:28.34 x 28.93 x 51.18 inches
- Item Weight:40.8 pounds
- Maximum Weight Recommendation:300 pounds
- Included Components:Arm Pad, Caster, Chair, Cushion, Headrest
- Number of Items:1
- Unit Count:1 Count
- Model Name:office chair
- Model Number:B300PRO-US-M2202
- Form Factor:Ergonomic
- Shape:Mesh, Ergonomic
- Theme:Office, Studio, Video Game
- Additional Features:Adjustable Backrest, Adjustable Headrest, Adjustable Height, Adjustable Lumbar, Ergonomic
- Recommended Uses For Product:Drafting, Gaming, Office, Reading, Relaxing, Sleeping, Study, Video Game
- Room Type:Bedroom, Drawing Room, Game Recreation Room, Office, Study Room
- Age Range Description:Adult, Teen
- Surface Recommendation:Hard Floor
- Indoor Outdoor Usage:Indoor
- Item Highlight:Adjustable Backrest &Seat Depth, 6D Flip-Up Armrests, 3D Wide Headrest,Breathable Mesh, 135° Recline, High Back, Grey
- Manufacturer Part Number:B300PRO-US-MS
- Material Type:Mesh
- Frame Material Type:Plastic
- Product Care Instructions:Wipe Clean
- Seat Material:Mesh
- Fill Material:Mesh
- Upholstery Fabric Type:Nylon, Polyester
- Furniture Base Movement:Swivel
- Reclining Position Count:110-135 Degrees
- Number of Height Positions:5
- Back Style:Ergonomic, Split Back
- Style Name:Modern
- Finish Types:Polished
- Arm Style:6D Flip-up
- Furniture Finish:Mesh
- Cushion Style:Curved Edge, Mesh
- Leg Style:Star Base
- Item Dimensions D x W x H:28.34"D x 28.93"W x 51.18"H
- Seat Back Interior Height:22.83 inches
- Seat Height:21.77 inches
- Seat Depth:18.5 inches
- Seat Length:19.09 inches
- Arm Height:28.93 inches
- Chair Backrest Width:19.48 inches
- Adjustable Seat Depth Maximum:18.5 inches
- Adjustable Seat Depth Minimum:16.53 inches
- Adjustable Seat Height Minimum:18.42 inches
- Adjustable Seat Height Maximum:21.77 inches
- Assembly Instructions Description:Attach The Wheelbase To The Gas Lift Cylinder, Mount The Seat Mechanism, Connect The Backrest, And Install The Armrests And Headrest
About this item
- ADJUSTABLE LUMBAR SUPPORT THAT MOVES WITH YOU Long hours at your desk can leave your lower back tense and unsupported. The B300 PRO ergonomic office chair uses a spring-assisted 4D lumbar support that adjusts in height and glides forward independently. It also flexes your body to maintain steady contact as you move. Lean forward for focused work, sit upright through meetings, or recline to recharge. The lumbar support follows every shift, helping ease pressure and keep you comfortably centered from morning to night.
- RAISE THE BACKREST. FIND YOUR FIT. Most chairs force your body to adapt to a fixed backrest. The B300 PRO does the opposite. Its independently height-adjustable backrest lets you position the lumbar support where your lower back needs it. The result is a more natural sitting position and fuller back contact for users of different heights. Whether you work from a home office or share a workspace, this ergonomic chair delivers a personalized fit that feels stable, balanced, and effortless throughout the day.
- SIT DEEPER. FEEL LIGHTER. A seat that is too shallow or too deep can leave your legs unsupported and make long hours feel even longer. Adjust the seat depth to match your leg length and create fuller thigh support. A better fit spreads body weight more evenly and helps ease pressure during extended sitting. Power through deadlines, study for hours, settle into a gaming session, or unwind with a book. The breathable mesh seat keeps air moving, so this desk chair helps you stay cool and comfortable without constant repositioning.
- RECLINE WITHOUT THINKING You should not have to adjust knobs every time you lean back. This computer chair uses a smart weight-sensing mechanism to match recline resistance to your body weight—no manual tension adjustment needed. Stay upright for focused tasks, lean back to think between meetings, or recline up to 135° for a quick reset. The chair follows your movement smoothly and stays balanced through every transition, so each position feels natural and supported.
- FULL-BODY SUPPORT, DESIGNED AROUND YOU Neck and shoulder tension can build when a chair supports only your back. The oversized 3D headrest adjusts to cradle your neck during long video calls, reading, or quiet moments of relaxation. The 6D armrests rotate, slide, lift, and flip up to meet your arms where they naturally rest. Type, create, game, or sit cross-legged with support that adapts around you. This flexible setup makes it easy to use as a focused office chair by day and a supportive gaming chair after hours.
- BUILT TO LAST. BACKED BY SIHOO. Built with premium materials and rigorously tested to meet BIFMA, SGS, and TÜV standards, the B300 PRO office chair is designed for dependable daily use. Every chair comes with a 3-year warranty and 30-day hassle-free returns, giving you confidence from day one. Choose with confidence and enjoy lasting ergonomic comfort every day.
Shipping Policy
ZenOffice ships from the United States.
Most orders leave the warehouse within 1 business day and arrive in 2–7 business days.
- Free shipping on orders of $200 or more, applied automatically
- Otherwise shipping is a flat $6.90
- Your tracking number is emailed as soon as your order ships
- We currently ship to the lower 48 United States
Return policy
30-day returns.
If it's not right for the room, you have 30 days from delivery to send it back, and ZenOffice will email you a return label. Return shipping fees may apply depending on the item's size, weight, and shipping location, and are deducted from your refund.
How it works
- Email us at support@zenofficeshop.com with your order number.
- We send a return label within 1 business day, along with the return shipping cost (if any) so you can decide.
- Your refund goes back to your original payment method within 10 business days of the carrier scan.
Items should be unused, unassembled, and in their original packaging. Damaged or defective on arrival? Send a photo and ZenOffice replaces or refunds immediately, return shipping on us, and in most cases you won't need to send anything back.

