Shimano xtr bb93 hollowtech ii bottom bracketshimano xtr bottom bracket is hollowtech ii and includes cups bearings and sleeve precision bottom bracket bearings are spaced further apart and are therefore more stable and longer lasting than conventional bottom brackets featuresgenuine shimano hollowtech ii bottom bracket assemblyset includes left and right hand cups spacers inner cover and inner o ringslight weight seal structure helps to remove vital gramssealed cups keep out dirt and w