The 5500 basic design of this manager's chair is an excellent example of simplicity at its best. The open air-grid back with built-in lumbar support conforms to your back for passive ergonomic support. The black mesh seat is thickly cushioned for enhanced comfort. Functions include pneumatic seat-height adjustment from 18-3/4" to 23" , 360-degree swivel and 2-to-1 synchro tilt control with adjustable tilt tension. Angled arms with soft pads are height-adjustable. Heavy-duty, angled nylon base has oversized, dual-wheel carpet casters. Seat size is 20-1/2" wide x 21" deep x 3-1/2" thick. Back size is 20-1/2" wide x 18-1/2" high. Distance between arms is 18-3/4". Professional Dark Air Grid Back Managers Chair is also Greenguard Indoor Air Quality Certified.The 5500 basic design of this manager's chair is an excellent example of simplicity at its best. The open air-grid back with built-in lumbar support conforms to your back for passive ergonomic support. The black mesh seat is thickly cushioned for enhanced comfort. Functions include pneumatic seat-height adjustment from 18-3/4" to 23" , 360-degree swivel and 2-to-1 synchro tilt control with adjustable tilt tension. Angled arms with soft pads are height-adjustable. Heavy-duty, angled nylon base has oversized, dual-wheel carpet casters. Seat size is 20-1/2" wide x 21" deep x 3-1/2" thick. Back size is 20-1/2" wide x 18-1/2" high. Distance between arms is 18-3/4". Professional Dark Air Grid Back Managers Chair is also Greenguard Indoor Air Quality Certified.