These esd or cleanroom chairs feature proper grounding, conductive, and dissipative static control materials and have been tested to meet ANSI or esd-STM-12.1-2006 and fed std.209e and iso 14644-1 requirement (class10 or iso class 4). Optional 6-way adjustable armrests support a variety of arm placements for proper ergonomics (note: adding arms changes the classification to class 100 or iso class 5). These polyurethane chairs are fully washable, making them ideal for almost any environment. Choose from esd rolling, non-marring casters, or esd, non-marring bell glides on a polished cast aluminum base. Optional seat tilt provides 8 forward and 3 backward locking tilts for ergonomic posture support.