Ergonomically designed production chairs and stools provide hours of comfortable seating. Standard on all seating: 18″ sq. seat, 16″W x 13″H back with 2-1/2″ thick foam padding, adjustable seat depth and reinforced black nylon bases with dual-wheel casters. Pneumatic height adjustment from 19 to 27″ for stools. Stool has adjustable chrome plated foot ring. Conductive Clean Room models meet Class 100, federal standard 209E. They have a three level filtration system, completely sealed cushions and chrome plated metal parts. Only the non-ESD fabric chairs are Scotchgard treated. Easy assembly.