Designed for superior support, this Ergonomic Office Chair features a world-first, fully adaptive lower back support system within its mesh backrest that automatically conforms to your spine. The lumbar support strength is manually adjustable and locks in 5 positions. It includes a headrest that adjusts 13cm in height and 30 degrees in angle, a backrest with 6cm of independent height adjustment, and locks into 4 recline positions (96°/116°/126°/136°). The chair is equipped with a rebound sponge cushion, 5cm seat depth adjustment, and 3D armrests. It features waterproof, anti-static fabric, a detachable iron five-star wheel base, a Class-4 hydraulic gas lift, and supports up to 300 lbs. Adult assembly is required with tools provided.