Our height-adjustable desk chair will grow with your little one(6-15 years old). The premium gas lift system and an adjustment lever allow the chair to easily lift up and down. Ergonomic backrest helps kids to develop a good sitting posture. Smooth armrests and elastic mesh seats add more sitting comfort. The breathable nylon mesh fabric ensures heat dissipation and excellent durability. Besides, the 360° swivel seat ensures easy changing direction. 5 flexible wheels allow for easy movement. The sit-brake wheels will automatically lock when the pressure is over 25kg and automatically lose when kids stand up.