Highly adjustable, durable Continuous-Use Stools stand up to continuous use during multiple shifts. Seat and back have steel inner frame and improved contoured extra soft form-molded polyurethane to promote proper posture. Self-skinned covering won’t crack under heavy use and is easy to clean. Sturdy polished aluminum base is 27" in diameter. 20" polished aluminum foot ring adjusts to accommodate multiple users. Seat adjusts pneumatically. Back adjusts manually. Lifetime guarantee on pneumatic cylinder. 15-year guarantee on stool. Ships via UPS.