Ergonomic mid-back chair features adjustable lumbar support, height-adjustable arms, a breathable mesh back and movable cushion seat. The seat-glide mechanism allows the seat cushion to travel forward and back from 17-1/4" to 19-5/8" and then locks into position. Armrests adjust 6" to 9" in height and are covered with polyurethane pads for your comfort. Other functions include 360-degree swivel, tilt, tilt tension, tilt lock and pneumatic seat-height adjustment from 18-5/8" to 23-3/8" high. The 19-3/4" wide seat is upholstered with fabric. Back size is 16-5/8" wide x 16-7/8" high. 27-2/5" diameter five-star base is made of glass-filled nylon and is equipped with 50mm hooded, dual-wheel casters for easy chair movement. Weight capacity is 250 lb.