Next Generation casters are maintenance-free casters made of glass-filled nylon. This gives extra durability and strength to the caster. Next Generation casters are resistant to most chemicals. Precision bearings are insert-molded into the sealed raceway, providing a worry-free, smooth and quiet operation. Wheels include full thread guards to reduce debris entanglement. Recessed axles are covered with plastic caps. Antistatic option provides additional antistatic properties to help reduce the chance of electrostatic discharge.