When strength is the most important issue for your casters, these are your answer. 6" and 8" phenolic caster provide impact resistance while giving incredible strength. Phenolic wheels are resistant to chemicals, non-marking and non-conductive. Larger size lets them roll more smoothly over rough surfaces. Available in swivel or rigid with a brake option for the swivel casters. Refer to chart for caster specifications. Features Chemical resistant Non-marking Impact resistant Ships USPS