The SIHOO DORO S100 ergonomic office features an innovative dual dynamic lumbar support system designed to provide all-day support and comfort. In addition, the independent backrest, oversized waterfall cushion with adjustable seat depth, and high-elasticity, highly supportive mesh ensure long-lasting comfort for all parts of your body, while the 4D coordinated armrests allow your arms and shoulders to rest in different positions. Features: - Dual dynamic lumbar support for all-around lower back comfort - Independent backrest ensures adequate support to entire back - 4D coordinated armrests to rest your arms in different postures - Premium elastic mesh that's breathable, supportive, and comfortable - Seat depth adjustment to better suit different heights Adjustable recline elasticity from 95° to 130° Includes 30-minute installation paper guide and installation video Includes all installation tools including gloves 6in overall height adjustment High-strength steel detachable chair base Fourth-grade gas lift tested by SGS and BIFMA ANSI/BIFMA X5.1-2017 (R2022), excluding arm strength test - vertical - static (proof load) Maximum weight capacity of 300 lbs Fits heights 5'3" to 6'3"