Shimano deore m610 10 speed triple chainsetgreat value deore 2 piece design chainset for 10 speed dyna sys mtb hg x transmissions 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 durable lightweight and rigid steel bottom bracket axle sg x chainring with patented spike pins give smooth and fast gear shifts under load lightweight aluminiu