1. Introduction
Thank you for choosing the Okeysen Armless Office Desk Chair. This manual provides essential information for the safe assembly, operation, and maintenance of your new chair. Please read all instructions carefully before use and retain this manual for future reference.
The Okeysen Armless Office Desk Chair is designed for comfort and functionality in various settings, including offices, study rooms, and conference rooms. Its ergonomic L-shaped design with integrated lumbar support helps relieve fatigue during extended periods of sitting. The armless design and adjustable height feature allow for optimal space utilization and compatibility with most desk sizes. Constructed with a stable five-star metal base and 360° swivel casters, it offers both durability and smooth mobility.
2. Important Safety Warnings
- Always assemble the chair according to the provided instructions.
- Do not exceed the maximum weight capacity of 330 lbs (150 kg).
- Ensure all screws and bolts are securely tightened before using the chair. Periodically check and re-tighten as necessary.
- Do not stand on the chair or use it as a step stool.
- Avoid exposing the chair to direct sunlight or extreme temperatures to prevent material degradation.
- Keep children away from moving parts during assembly and adjustment.
3. Package Contents
Before beginning assembly, please ensure all components are present and undamaged. If any parts are missing or damaged, please contact customer service.
- Seat and Backrest Assembly
- Five-star Metal Base
- Casters (5 pieces)
- Gas Lift Cylinder
- Mechanism Plate
- Assembly Hardware (screws, washers, Allen wrench)
- User Manual
4. Assembly Instructions
Assembly of this chair typically takes approximately 15 minutes. Follow these steps carefully:
- Attach Casters to Base: Insert each of the five casters into the holes at the end of the five-star metal base until they click securely into place.
- Insert Gas Lift: Place the gas lift cylinder into the center hole of the assembled five-star base.
- Attach Mechanism Plate to Seat: Align the mechanism plate with the pre-drilled holes on the underside of the seat. Secure it using the provided screws and Allen wrench. Ensure the adjustment lever faces the front of the seat.
- Connect Seat to Gas Lift: Carefully place the assembled seat (with mechanism plate) onto the top of the gas lift cylinder. Press down firmly to ensure a secure connection.
Video: Official Okeysen Armless Office Desk Chair Assembly Guide. This video demonstrates the step-by-step assembly process for the chair, including attaching the base, gas lift, and seat.

Image: Fully assembled Okeysen Armless Office Desk Chair in black, showcasing its sleek design and armless feature.
5. Operating Instructions
5.1. Height Adjustment
To adjust the seat height, locate the lever on the right side beneath the seat. While seated, pull the lever upwards to lower the seat. To raise the seat, lift your weight off the seat and pull the lever upwards. Release the lever at the desired height to lock it in place.

Image: Visual guide illustrating the height adjustment lever and tilt tension control knob located beneath the seat.
5.2. Tilt and Tension Control
The chair features an extra rocking mode for comfort. To adjust the tilt tension, locate the round knob at the front, beneath the seat. Turn the knob clockwise to increase tension (making it harder to recline) or counter-clockwise to decrease tension (making it easier to recline).
5.3. Swivel and Mobility
The chair is equipped with 360° swivel casters, allowing for easy rotation and smooth movement across various floor surfaces, including carpet and hard floors.

Image: Detailed view of the chair's mute rubber casters designed for floor protection and smooth movement.
6. Maintenance
6.1. Cleaning Instructions
To clean your Okeysen Armless Office Desk Chair, simply wipe it clean with a damp cloth. Avoid using harsh chemicals or abrasive cleaners, as these may damage the PU leather material.
6.2. Regular Inspection
Periodically inspect all bolts and screws to ensure they remain tight. Re-tighten any loose fasteners to maintain the chair's stability and safety.
7. Specifications
| Feature | Detail |
|---|---|
| Brand | Okeysen |
| Model Name | Okeysen Armless Office Desk Chair |
| Model Number | C039-BK |
| Color | Black |
| Product Dimensions | 18.5"D x 19.69"W x 38.96"H |
| Seat Height | 17.32 - 21.26 Inches (Adjustable) |
| Seat Depth | 18.5 inches |
| Seat Length | 19.69 Inches |
| Chair Backrest Width | 17.72 Inches |
| Maximum Weight Recommendation | 330 Pounds (150 kg) |
| Material | PU Leather, Cotton, Foam |
| Special Features | Adjustable Height, Ergonomic, Rolling, Swivel |
| Included Components | Casters, User Manual |
| Assembly Instructions | Assembly required, instructions included |

Image: Detailed dimensions of the Okeysen Armless Office Desk Chair, including back height, seat height, and weight capacity.

Image: Illustration highlighting the ergonomic lumbar support feature of the chair, designed to align with the spine's natural curve.
8. Troubleshooting
If you encounter any issues with your Okeysen Armless Office Desk Chair, please refer to the following common solutions:
- Chair is wobbly: Ensure all assembly screws and bolts are securely tightened. Check that the casters are fully inserted into the base.
- Height adjustment not working: Verify that the gas lift cylinder is correctly installed and the lever mechanism is functioning properly. Ensure no obstructions are preventing movement.
- Casters not rolling smoothly: Check for any debris (hair, dust) caught in the casters and clean them if necessary. Ensure the chair is on an appropriate surface.
For further assistance, please contact Okeysen customer support.
9. Warranty and Support
Okeysen is committed to customer satisfaction. While specific warranty details are not provided in this manual, please retain your proof of purchase. For any product inquiries, technical support, or warranty claims, please contact Okeysen customer service through the retailer where the product was purchased or visit the official Okeysen website for contact information.