SIHOO M18 Ergonomic Office Chair User Manual

1. Introduction

Thank you for choosing the SIHOO M18 Ergonomic Office Chair. This manual provides detailed instructions for assembly, operation, and maintenance to ensure you get the most comfortable and supportive experience from your new chair. The SIHOO M18 is designed to provide optimal ergonomic support for users, especially those who are big and tall, promoting a healthy sitting posture during long hours of work or study.

Figure 1: SIHOO M18 Ergonomic Office Chair

2. Safety Information

Please read all instructions carefully before assembly and use. Keep this manual for future reference.

• Do not stand on the chair.
• Do not use the chair as a step stool.
• Ensure all bolts and screws are tightened securely before use. Periodically check and re-tighten as necessary.
• Do not use the chair if any parts are missing, damaged, or worn.
• Keep children away from moving parts.
• The maximum weight recommendation for this chair is 150 kg (330 lbs).

3. Parts List

Before beginning assembly, ensure all parts are present and undamaged. Refer to the diagram below for identification.

Figure 2: SIHOO M18 Packaging (components inside)

1. Chair Base (1)
2. Casters (5)
3. Gas Lift Cylinder (1)
4. Seat Cushion (1)
5. Backrest (1)
6. Armrests (2)
7. Headrest (1)
8. Hardware Pack (screws, washers, tools)

4. Assembly Instructions

Assembly is simple and can be completed in eight easy steps. A T-style tool is included for convenience.

1. Insert the casters into the holes at the end of each leg of the chair base.
2. Place the gas lift cylinder into the center hole of the chair base.
3. Attach the armrests to the seat cushion using the provided screws. Ensure they are securely fastened.
4. Attach the backrest to the seat cushion assembly.
5. Carefully place the assembled seat and backrest onto the gas lift cylinder.
6. Insert the headrest into the top of the backrest.
7. Tighten all screws to ensure stability.
8. Test all adjustments before regular use.

5. Features & Adjustments

The SIHOO M18 chair offers multiple adjustment points for personalized comfort and ergonomic support.

5.1 Adjustable Headrest

Figure 3: Adjustable Headrest

The headrest can be adjusted vertically by 3.15 inches and rotated 45 degrees to effectively support your head and relax your neck, promoting a comfortable posture.

5.2 Adjustable Armrests

Figure 4: Adjustable Armrests

The 2D armrests can be adjusted in height (up to 2.8 inches) to find the most appropriate position, reducing fatigue in your arms and shoulders during prolonged use.

5.3 Lumbar Support

Figure 5: Adjustable Lumbar Support

The lumbar support is adjustable both vertically (up to 2.17 inches) and horizontally (up to 1.77 inches) to effectively share lumbar muscle pressure and relieve work strain. This helps improve the shape of your lumbar vertebrae and supports a healthy sitting posture.

5.4 Tilt Function

Figure 6: Tilt Adjustment

The chair features a tilt function with three hard-set recline positions: 108° for focused work, 118° for immersion reading, and 128° for a relaxing lunch break. A spring release recline mechanism ensures smooth transitions.

5.5 Seat Height Adjustment

Adjust the seat height using the lever located under the seat to ensure your feet are flat on the floor and your thighs are parallel to the ground. This chair is suitable for people 5'6" to 6'2" tall.

5.6 S-shaped Chair Back Design

Figure 7: S-shaped Back Design

The S-shaped chair back design provides accurate fit and effective support, protecting the human spine and promoting a healthy office posture.

5.7 Breathable Mesh & High Elastic Sponge Cushion

Figure 8: Seat Cushion Material

The premium backrest features flexible non-pattern mesh fabric, keeping your back cool and comfortable. The seat cushion is made of high elastic sponge with rebound decompression properties, ensuring comfort and preventing collapse over time.

6. Operating Instructions

To operate your SIHOO M18 chair, utilize the levers and knobs located beneath the seat and on the backrest for various adjustments. Always ensure you are seated properly before making adjustments to avoid injury.

• Height Adjustment: Pull the lever on the right side of the seat upwards while applying or releasing weight to adjust the seat height.
• Tilt Lock/Unlock: Use the lever on the left side of the seat to lock the backrest in an upright position or unlock it for reclining.
• Tilt Tension: Rotate the round knob under the seat to adjust the tension of the recline, making it easier or harder to lean back.
• Armrest Height: Press the button on the side of each armrest and slide them up or down to your desired height.
• Headrest Adjustment: Grasp the headrest and slide it up or down, or tilt it forward/backward to find optimal neck support.
• Lumbar Support Adjustment: Use the knobs on the backrest to adjust the lumbar support's height and depth for personalized lower back comfort.

7. Maintenance

Regular maintenance will prolong the life and appearance of your SIHOO M18 chair.

• Cleaning: Wipe mesh and plastic surfaces with a damp cloth and mild soap. Avoid harsh chemicals.
• Inspection: Periodically check all screws and bolts to ensure they are tight. Re-tighten if necessary.
• Casters: Clean casters regularly to prevent dust and hair buildup, ensuring smooth movement.

8. Troubleshooting

If you encounter any issues with your SIHOO M18 chair, refer to the common problems and solutions below.

• Chair Sinks/Doesn't Stay Up: Ensure the gas lift cylinder is properly installed. If the issue persists, the gas lift may need replacement.
• Chair Wobbles: Check all assembly screws and bolts. Tighten any loose connections. Ensure the base is level on the floor.
• Casters Don't Roll Smoothly: Clean any debris (hair, dust) from the casters. Lubricate if necessary.
• Backrest Doesn't Recline/Lock: Check the tilt lock lever and ensure it's in the correct position. Adjust the tilt tension knob.

For further assistance, please contact SIHOO customer support.

9. Specifications

10. Warranty & Support

Customer satisfaction is our first priority. SIHOO offers free returns and refunds within 30 days if the office chair is faulty or if there are any other quality-related issues. We promise to provide free replacement parts during the 3-year warranty period.

If you encounter any problems or have questions, please contact us. We are committed to providing satisfactory solutions.

• Warranty Period: 3 years (free replacement parts)
• Return Policy: Free returns and refunds within 30 days for faulty or quality-related issues.