Onyx High Back Ergonomic Posture Chair with Height Adjustable Arms
Free UK Delivery
Free standard delivery on all orders to UK mainland. Delivered within 3–7 working days.
30-Day Returns
Return your item within 30 days of delivery for a full refund. Items must be unused and in original packaging.
The Onyx is a fresh, contemporary ergonomic posture chair that blends striking design with a comprehensive suite of adjustments — making it the ideal choice for anyone serious about comfort and support in their home office. Its multi-functional asynchronous mechanism allows the seat and backrest to move independently, adapting to your every movement throughout the day.
The contoured foam seat and back provide excellent support and cushioning, while the height-adjustable lumbar support and seat slide ensure a truly personalised fit. An optional adjustable headrest completes the package for those who need full upper-body support during long working sessions. Available in Black Fabric, Black Leather, Bespoke Stevia Blue Fabric, and Bespoke Maringa Teal Fabric. Over 20 additional bespoke fabric colours available — contact us for alternatives.
Key Features
- ✅ Multi-functional asynchronous mechanism
- ✅ Independent seat & back tilt with tilt tension adjustment
- ✅ Seat slide & seat angle adjustment
- ✅ Height-adjustable backrest with permanent contact
- ✅ Integral & adjustable lumbar support
- ✅ Height-adjustable arms (removable)
- ✅ Optional adjustable headrest available
- ✅ Contoured foam seat & back for extra comfort
- ✅ 24-hour usage rated
- ✅ 135kg maximum weight capacity
- ✅ Chrome metal frame
- ✅ Available in fabric or bonded leather upholstery
Specifications
- Overall Dimensions: W650 × D670 × H1020–1140mm (without headrest) / H1180–1430mm (with headrest)
- Seat Dimensions: W440 × D460–510mm
- Seat Height: 495–570mm
- Back Dimensions: W430 × H530–580mm (without headrest) / H690–840mm (with headrest)
- Arm Height: 635–735mm
- Product Weight: 22kg (without headrest) / 23kg (with headrest)
- Max Weight Capacity: 135kg
- Recommended Usage: 24 hours
- Frame Material: Chrome Metal
- Self Assembly Required: Yes
Guarantees
- Mechanical Components: 5 Years
- Fabric & Foam: 2 Years
Test Certificates
BS 5459 · BS 5852 Ignition Source 5 (Crib 5) · EN 1021-1 · EN 1021-2 · BS 7176 Low Hazard
Delivery & Installation
- 🚚 Next Day Delivery Available
- 🔧 Professional Installation Service Available — contact us to add this to your order
Shipping & Delivery
Free Standard Delivery on all orders to UK mainland — no minimum spend.
Delivery timescales:
- Standard items: 3–5 working days
- Large / bulky items (furniture, garden structures): 5–7 working days
- Made-to-order or special items: up to 14 working days
Kerbside delivery applies to large items. Please ensure someone is available to receive the delivery.
Tracking: You will receive an email with tracking information once your order has been dispatched.
Scottish Highlands, Northern Ireland & Islands: Additional charges may apply. Please contact us at customer.care@homesplex.com or call 03330 904 195 before ordering.
Returns & Refunds
We want you to be completely happy with your purchase. If you are not satisfied, you can return most items within 30 days of delivery for a full refund.
How to return:
- Email us at customer.care@homesplex.com with your order number and reason for return
- We will send return instructions within 1 working day
- Items must be unused and in original packaging
- Refund processed within 5–7 working days of receiving the item
Faulty or damaged items: Contact us immediately with photos and we will arrange a replacement or full refund at no cost to you.
Contact us at customer.care@homesplex.com or call 03330 904 195.