POBCO Plastic Idlers Split design for use of 820, 821, 880, 880TAB, 882 and 882TAB Chains Heavy Duty - Chemical ResistantSpecial Features: Self TrackingFixed or Free RunningRigid and ToughUltra-High Loading CapacitySilent RunningNo Lubrication90% Less weight than steelClean and HygienicMaintenance FreeResistant to most chemical and corrosive conditionsFor Steel or Plastic ChainMay Be Keyed to Shaft or Free-Wheel