Contoured seat and back provide added comfort for long hours at your desk. Optional Adjustable T-Arms kit sold separately. Manufacturer's five-year limited warranty. Adjust seat and back angles with a single lever. Pneumatic seat height adjustment. 360° swivel. Adjustable back height. Black five-star base with casters. Seat: 21w x 18d. Back: 18w x 18h. Overall height 33" to 37". Shpg. wt. 31 lbs. Assembly required. Casters supplied with this chair are not suitable for all floor types. Alternative casters are available to meet your specific needs.