BEVCO's Everlast ESD/ISO 4 Cleanroom chairs are designed for outstanding comfort and long-lasting use while meeting specific particulate goals of ISO 14644-1 and ESD requirements of ANSI/ESD STM12.1-2019 to deliver a combination ESD/Cleanroom seating solution for highly technical environments. The black ESD polyurethane seat and back are static dissipative; anti-bacterial; 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 20.5" - 30.5". This chair comes with a sturdy 27" diameter polished aluminum base with brass drag chain and adjustable ESD footring. Model comes standard with ESD mushroom glides. Optional ESD casters can be ordered separately.