Ergonomic Design:This office chair boasts an extra-wide, adjustable headrest that can be fine-tuned in both height and angle to offer optimal neck support. The broad backrest conforms to the spine, providing stable shoulder support. This ergonomic chair effectively prevents back pain by supporting the spine's natural curve and aiding in posture correction, ensuring a comfortable and healthy seating experience. Exceptional Seating Comfort:The seat cushion is made from high-quality, thick foam that matches the body's contours, distributing weight evenly across the hips and thighs. The front edge, crafted from molded foam, prevents sinking and leg numbness during long sitting periods. The backrest, made of high-elastic breathable mesh, ensures cool comfort. Silent wheels allow smooth movement, protecting floors from scratches. Adjustable for All Heights:The backrest tension can be adjusted via a knob, while both the armrests and seat height can be modified by 8 to 10 centimeters to accommodate different heights. The adjustable lumbar support adapts to the lower back, providing excellent lumbar spine support and reducing spinal pressure. Users can customize settings to find the most comfortable position, ensuring optimal back support. Practical and Comfortable:This ergonomic office chair features a reclining backrest that can tilt between 95° and 120°. Whether you use it as a computer chair, office chair, gaming chair, executive chair, or meeting chair, it provides an unparalleled seating experience. Detailed instructions enable easy assembly within 15-20 minutes, allowing you to quickly enjoy its benefits. Reliable Service:When you purchase this ergonomic desk chair, you receive a 2-year free warranty. For any defects not caused by human error, contact us by logging into your Amazon account, selecting "Your Orders," finding the order ID, and clicking "Contact Seller." We promise to provide a prompt and professional solution within 24 hours, ensuring complete satisfaction. Note: Accessory K and Accessory B are packaged together upon receipt. To install the spilt base tube, you will need to pick up accessory K and then attach thespilt base tube to accessory B with the screws.