1 Each. Shell Extended-Height Chair offers intuitive adjustments and a sleek design that fits into any space. With extended seat height from 22" to 32" , it pairs well with standing or adjustable-height desks to help promote more movement and a more active workday. Flat, adjustable footring around the base gives you support while sitting. Contoured plastic back delivers lumbar support. Seat naturally flexes to fit you comfortably. Black vinyl on the seat and arms provides another layer of comfort. The vinyl is also easy to clean. Holes in the back allow breathability. Casters on sturdy, five-star nylon base and 360-degree swivel capabilities make mobility easy.