Mid-back chair features a breathable mesh back with adjustable lumbar support and cushioned seat that is fabric-upholstered. Versatile arms flip up and out of the way. Functions include pneumatic seat-height adjustment from 16-3\/4" to 20-7\/8" , 360-degree swivel, tilt and tilt lock. Nylon five-star base is equipped with 50mm dual-wheel, hard casters for easy chair movement. Seat measures 20-1\/2" wide x 16-1\/2" deep. Back size is 20-1\/2" wide x 20-1\/8" high. Weight capacity is 250 lb.