ALVIN - MONARCH Executive Office Chairs - Designed for the ultimate in style, comfort and construction, the MONARCH chair has contoured cushions and other ergonomic features that make it an outstanding value. High backrest provides solid orthopedic spine support and full-size upholstered seat is contoured for added comfort. Features incude pneumatic height control, polypropylene seat and back shells, a height and depth-adjustable backrest with tilt angle control, adjustable seat pitch, dual wheel casters and a 23" diameter steel reinforced nylon base. Seat cushion is 19"w x 18"d x 3" thick. Backrest is 16"w x 19"h x 3" thick. Office model height adjusts from 18" to 23". Optional armrests available.