Adjustable, inflatable lumbar support enables chair back to conform to the natural curve of the user’s back. Pushbutton design allows easy inflation/deflation to desired comfort level. Pneumatic seat height control. Tilt tension and tilt lock. Upholstery has stain-resistant protection. Black, oval steel tube frame with injection molded base. Seat: 21-1/4w x 19-1/2d. Back: 21-1/4w x 23-3/4h. Overall height 39-1/2" to 43-1/2". Shpg. wt. 43 lbs. Assembly required. Meets or exceeds ANSI/BIFMA standards. Manufacturer’s limited lifetime warranty. Alternative casters are available to meet your specific needs. Casters supplied with this chair are not suitable for all floor types.