Ergonomically designed production 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. ESD models are static-dissipative with a resistance of less than 106 ohms, and have a drag chain for proper grounding. Only the non-ESD fabric chairs are Scotchgard treated. Easy assembly.