Circulation Stack & Laptop or computer Chair The Circulation Stack chair marries type and comfort and ease in a exclusive, present day bundle. The seat and back again are injection-molded polypropylene contoured to present a at ease suit. Offered in black or gray, the Circulation Stack chair is offered in sets of 4. Include a set of optional casters and generate a Personal pc activity chair. Optional arms are Out there individually, and demand assembly to the chair.