The CT580 Orthopedic Premium Mesh Back Executive Chair; relieves back pain, tailbone pain and pelvic pain. Patented seat design with 2.5" wide recessed channel; elevates the spine and pelvic floor eliminating upward pressure when sitting. Upholstered with a unique Web mesh material which allows air to pass through, adding to long-term comfort by preventing body heat and moisture buildup. The web back distributes weight evenly, and provides the perfect level of back support by conforming to each individuals back shape. The Web-Tension Knob (located underneath the seat) allows the user to tighten or loosen the tension of the mesh material with a few simple twists. Pneumatic gas lift seat height adjustment, Adjustable tilt tension control. Large 27 nylon base for greater stability, Hooded double wheel casters, Adjustable height armrests. Seat Size: 19-1/8W x 19-1/8D. Weight Capacity: 250lbs. Recommended for people 5'-10" or taller.