ERGONOMIC DESIGN: Having a chair with lumbar support is especially necessary for all-day working and studying. This ergonomic office chair will not only help to sit at correct sitting postures but also help relieve stress and reduce fatigue after long-time sitting. The curved backrest design line up with the human body's spine natural curve to provide low-back support. COMFORTABLE SEAT: Several detail designs to provide long-lasting comfort. Ergonomic armrest with suitable height to allow users to put hands on top to relax. High-density sponge seat with sufficient seat depth to reduce pressure on the user's hips. Breathable mesh back and seat allow airflow to help users stay cool during a long time studying. ADJUSTABLE HEIGHT: With 2.75 Inches adjustable seat height, this office chair can be adjusted from 33.5" to 36.25" to match with your home or office desk. Pneumatic controls make our office chair easier to raise or lower - simply pull up the lever and adjust the seat at your desired height.