Features proper grounding, conductive, and dissipative static control materials and have been tested to meet ANSI/ESD-STM-12.1-2006. They are manufactured to promote the grounding of electricity so no static discharge can occur. The intention is to move any potential static electricity from the item that is being worked on in instances where manufacturing of sensitive equipment and instrumentation occurs. Foam cushion is covered by black static-dissipating vinyl. ESD non-marring casters suitable for both hard and carpeted floors. Weight Capacity: 300 lbs.