Adjustable Task Chairs offer a pneumatic seat-height, back height, seat depth, 360-degree swivel and arms that adjust in height and width. Molded seat and back allow comfort for all-day use. Durable shellback and seat allow for clean smooth lines. Adjustable back provides support where you need it. Abrasion rating is 30,000 cycles. Seat-to-floor dimensions measure 17-3/10" to 22-2/5". Fully Adjustable Ergo Chairs