Safety Guarantee:Ergonomic chair's class 4 gas clylinder is SGS/TUV certified and BIFMA-tested for reliable height adjustment, while the reinforced metal base supports up to 400 lbs with sturdy stability. Multi-angle reclining: This office chair features an adjustable reclining function, which can help you relieve work fatigue. Paired, it also enables you to easily switch between work mode and rest mode. Breathable mesh seat: The mesh material is durable, resistant to wear and deformation, and can keep you cool even during long periods of sitting still. Adaptive lumbar support: It can fit the natural curve of the spine without manual adjustment. You will enjoy tailor-made waist comfort, thereby reducing the pressure on your waist during long working hours. Flip armrests: The armrests of this ergonomic chair have a flip function, allowing you to store them in your desk after work and save space