Now you can adjust seat height in the middle of a procedure, with a simple tap of the foot. A 360 degree ring adjusts height pneumatically from any position. Comfortable Soft Feel cushion is 4 1/2 thick. The anti-microbial vinyl is treated with Perma Block 3 stain- resistant coating. Aluminum base with dual-wheel nylon casters. Height range: 19 1/2-24 1/2.Specify upholstery color when ordering.Choose from Vinyl Color Options : Windsor Wine, Cambridge Blue, Black, Emerald, Ninja, Smoke, Fawn, Mountain Violet, and Earthen Brown.