Shimano BB71-41B MTB Press-Fit Hollowtech II Bottom Bracket - Complete XT level press-fit bottom bracket assembly for Shimano HollowTech II MTB cranks. - Cups are made from fibre reinforced polymer material which reduces the risk of frame noise and damage. - Set includes left and right hand cups, 2.5 mm spacer, inner cover, and inner O-rings. - Sealed cups keep out dirt and water. - Maintenance free. - Compatible with 89.5 mm (with 2.5 mm spacer) and 92 mm shells. - 41 mm cup diameter. - Easy press-fit installation.