Ergonomically designed production chairs 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 17-1/2 to 22-1/2" for chairs. This ESD model is static-dissipative with a resistance of less than 106 ohms, and has a drag chain for proper grounding. Easy assembly.