| 1 | Seat Height Range | The seat should allow users to keep both feet flat on the floor while maintaining approximately a 90–110° angle at the knees. | A pneumatic seat-height range of approximately 40–55 cm is suitable for many adult users, but the ideal range depends on the user population and desk height. | Compare the chair range with the desk height and the expected user height range. Request dimensional drawings or a physical sample. | High |
| 2 | Seat Depth and Width | The seat should support the thighs without pressing behind the knees and should provide enough room for natural posture changes. | A seat width of about 45–52 cm and a usable seat depth of about 40–48 cm commonly accommodate a broad adult population. | Measure usable cushion dimensions rather than the outside frame. Confirm whether seat depth is adjustable for different body sizes. | High |
| 3 | Lumbar Support | The backrest should support the lower back and encourage a neutral spinal posture without creating concentrated pressure. | Look for adjustable lumbar height and, where available, adjustable depth or tension. A backrest height of approximately 50–65 cm can provide broad support. | Test the lumbar adjustment range while seated. Confirm the adjustment mechanism remains stable during reclining and daily use. | High |
| 4 | Backrest Recline and Synchro-Tilt | The chair should permit movement between upright work and reclined positions while keeping the body supported. | A recline range of approximately 90–120° or greater, with a lockable upright position and adjustable resistance, supports varied work tasks. | Check whether the backrest reclines smoothly, whether the seat angle is coordinated, and whether the tilt mechanism is suitable for the intended user weight. | High |
| 5 | Armrest Adjustability | Armrests should support the forearms while allowing the shoulders to remain relaxed and the elbows to stay close to the body. | Height adjustment is a basic requirement. Two-dimensional or four-dimensional adjustment can improve compatibility with different desks, users, and working styles. | Verify height, width, depth, and pivot functions where applicable. Ensure the armrests fit under the target desk when lowered. | High |
| 6 | Seat Cushion and Materials | The cushion should distribute pressure evenly, maintain support over time, and avoid excessive heat or moisture retention. | High-resilience molded foam or a durable suspension seat can provide consistent support. Breathable textiles or mesh may improve thermal comfort in warm climates. | Request foam density, resilience, fabric composition, abrasion data, and cleaning instructions. Test for pressure points after extended sitting. | High |
| 7 | Base, Casters, and Floor Compatibility | The base and casters should provide stable movement without damaging the intended floor surface. | A five-star base is widely used for stability. Soft casters generally suit hard floors, while harder casters may be appropriate for carpeted surfaces. | Confirm caster diameter, braking behavior, load rating, and compatibility with wood, tile, vinyl, or carpet. Consider replacement availability. | High |
| 8 | Load Capacity and Durability | The chair should safely support the intended users and withstand repeated adjustment, reclining, and rolling cycles. | Select a rated capacity with a practical safety margin above the expected user weight. Commercial-use chairs should be evaluated for repeated daily operation. | Review test reports, cycle-test results, warranty terms, and the stated capacity of the gas lift, tilt mechanism, base, and casters. | High |
| 9 | Safety and Compliance | Materials, structural components, and moving mechanisms should meet the safety expectations of the destination market. | Request applicable performance and safety documentation, such as recognized office-chair testing standards, chemical emissions data, and fire-safety information where required. | Confirm the exact tested model, not only a similar product. Check labeling, manuals, conformity documents, and destination-country requirements. | High |
| 10 | Packaging, Assembly, and After-Sales Support | The product should arrive undamaged, assemble efficiently, and remain serviceable throughout its expected life. | Prioritize protective packaging, clear multilingual instructions, replaceable components, spare-part access, and a clearly defined warranty process. | Review carton dimensions, shipment weight, assembly time, replacement-part lead times, warranty coverage, and return procedures before placing a bulk order. | High |
