Ergonomic Backrest Design: Curved backrest can flawlessly line up with the human body curve and support your spines natural curve. The lumbar support system provides consistent support to your lower back User-friendly Armrests: The ergonomic armrests provide you with all-time support for your arms and enable you to sit more cozily, getting rid of your fatigue after a long days hard work Robust Chair Construction: This mid-back office chair is constructed of hard-wearing polyester mesh, nylon star base, solid rolling casters and steel gas cylinder. It has passed BIFMA X5.1 Test and is recommended for office use for customers under 300 lbs Larger Seat for Optimal Comfort: In this model, we upgraded the seat size, measuring 51.5cm/20.3 (width) by 45cm/17.7 (depth), and 8cm/3 thick, to provide you with a softer and larger sitting area Reclining Office Chair: By simply pushing the lever or pulling it out, this mesh office chair can be tilted and leaned backward or locked in