Bevco 6001A5-4550S/5 Advanced Ergonomic Deluxe Chair with Casters, Tilt Back Adjustment, 18" to 23" Height Adjustment, Blue Pneumatic seat height adjustment Sturdy black, scuff resistant, reinforced plastic base with heavy duty glides Roomy, comfortable seat with waterfall front evenly supports legs and thighs Large contoured backrest with polypropylene back shell provides excellent durability and lumbar back support