Heavy-Duty Task Chair features a strong, 27" steel base with 2" dual-wheel casters for durable support & easy mobility. Adjustable arms on the chair can be moved up or down to ensure a perfect fit for most users regardless of height or the length of their arms. Pneumatic gas lift provides easy seat-height adjustments to help you find the personalized sitting style that suits you & your work environment. Spring-tilt mechanism allows you to change the angle of the entire seat relative to the floor & to transfer some of your upper body weight to the backrest of the chair. Task chair supports up to 400 lb.