Features cold-forged and CNC-machined alloy cups, dual-labyrinth bearing covers and precision sealed bearings Designed to fit all 24millimeter crank spindles and frames with 68 or 73 x BC 1.37-inch bottom bracket shells Compatible with Box Three, Box Four, Shimano HollowTech II, and RaceFace XType 3rd party web sales must be an Authorized Dealer