This Shimano BB71 mountain bike bottom bracket features cups that are made from a fibre reinforced polymer material, which reduces the risk of frame noise and damage. It also comes equipped with sealed cups that keep out dirt and water, making it suitable for all-weather and terrain conditions. Technologies: – Cups are made from fibre reinforced polymer material which reduces the risk of frame noise and damage. – Set includes left- and right-hand cups, 2.5mm spacer, inner cover, and inner O-rings. – Sealed cups keep out dirt and water. – Maintenance-free. – Compatible with 89.5mm (with 2.5mm spacer) and 92mm shells. – 41mm cup diameter. – 24mm inner bearing diameter. – Easy press-fit installation. – Shimano XT.