The 520 ERV7 chain boasts a 3% higher tensile strength due to stronger inner side plates and thicker pinsDue to increased X-Ring durability, the ERV7 sees a 13% wear resistance increase Maximum Engine Displacement (Offroad)1000 ccMaximum Engine Displacement (Street)1000 ccModelERV7 SeriesProduct NameDrive ChainSeal TypeX-RingTypeChainUnitsEachVendor part number4525516361231