Genuine Shimano replacement part. For use with Shimano Deore XT FC-M780 10spd Triple Chainset - 42-32-24T. Can also use 42T Outer Chainring from FC-M980, FC-M770-10 & FC-M660-10 these are a "B" match which indicates that the parts are usable, but differ in materials, appearance, finish & size etc.