Shimano Hollowtech IISA Mega Exo RaceFace X-TypeRotor 3D, Agilis, Rex 3 INFO Bottom Bracket Shell c-bear ceramic bearings Diameter Width Material Installed 46 mm 68 mm (Road)73 mm (MTB) Precision CNC aluminium cups √ Suitable for: Specialized carbon OSBB frame with the new XTR crank Parlee Z3 Shimano Hollowtech II MTB crank Specialized S-Works Epic 29 Ridley helium SL withDura Ace 9000 crank