BEVCO's Everlast Electrostatic Dissipative (ESD) or Static Control Chair models meet ANSI/ESD STM12.1–2019 standards providing fully grounded peace of mind. 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 non-tilt model features manual back and seat height adjustments 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.