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 requirements (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 tilt for ergonomic posture support.