SIHOO M57 Ergonomic Office Chair with 3 Way Adjustable Armrests, Lumbar Support, and Headrest, High Backrest, Tilt Function

[Ergonomic Design] The SIHOO ergonomic chair features all the characteristics of an ergonomic design. The S-shaped backrest design mimics the human spine and provides full back support. The adjustable headrest supports the neck, offering long-term comfort and perfect support for our health-conscious customers. The ergonomic office chair is easily adjustable, with a tilt range of 110°-116°-126° and an 8cm height adjustment range to help you find your ideal position. [3D Armrest] Unlike 2D armrests, 3D armrests can be raised and lowered in 5 positions, and the PU leather armrest surface can also be adjusted back and forth and rotated left and right as your seating position changes, providing multi-angle support for your hands, allowing you to maintain a healthy, comfortable posture while gaming, streaming, working, or napping. [Mesh material] The resilient foam at the front of the seat cushion and its curved design provide ample support while sitting. The seat and backrest are made of polyester mesh, which is durable and breathable, offering support while keeping you cool and sweat-free on hot summer days. [High Quality & Easy Assembly] Every part of this computer office chair has undergone rigorous safety and quality testing, including cushion impact tests, armrest fatigue tests, and chair base static pressure tests. The gas lift of this high-back office chair is BIFMA certified and can support up to 150 kg (330 lbs) of weight. The easy-to-follow instructions allow anyone to assemble this ergonomic executive chair in just 7 simple steps. [SATISFACTION GUARANTEE] Customer satisfaction will always be our top priority. Free returns and refunds are available within 30 days if the SIHOO office chair is defective or if there are any other quality-related issues. We promise to provide you with free replacement parts during the 3-year warranty period. If you have any problems, please contact us and we will do our best to help.