Shimano deore m612 10 speed triple chainsetgreat value deore 2 piece design chainset for 10 speed dyna sys mtb hg x transmissions intuitive dyna sys gear combination bring rider bike and trail together rider tuned fit various bike and riding style by choice of gear combination please note external hollowtech ii bottom bracket is included features the 2 piece design chainset features an external bottom bracket system which is a lightweight rigid design that is incredibly strong and durabl