Breathable Mid-Back DesignFeaturing densely knitted mesh backrest, this mesh office chair allows better airflow, accelerating heat and moisture dissipation. Mid-back design supports your spine's natural curve and protects your lower and middle back as it prompts you to sit straight. Adjustable Seat HeightThe seat height of this computer mesh chair can be simply adjusted from 35cm/13.8 to 45cm/17.7 by a little push-up/press down at the lever under the seat according to your needs.