BEVCO's Everlast ESD/ISO 4 Cleanroom chairs are designed for outstanding comfort and long-lasting use in highly technical environments. The black ESD polyurethane seat and back are static dissipative and are impervious to water, oil, and most chemicals, puncture resistant and easy to clean. This articulating tilt model features simultaneous seat and back adjustments to properly position the angle of the chair for increased comfort during extended sitting durations. The waterfall seat aids in lower body circulation, improving overall wellness. The pneumatic height adjustment allows you to easily change your seat height from 24" - 29". This chair comes with a sturdy 22" diameter chrome tubular steel base with brass drag chain and welded footring. Model comes standard with ESD mushroom glides. Optional ESD casters can be ordered separately.