Specifically designed for installing Shimano 24mm spindle diameter cranks in Cannondale BB30A (42mm ID, 73mm wide asymmetrical BB shell) frames without the need for any adapters Two machined aluminum cups thread together ensuring the bottom bracket remains stable in the frame, increasing bearing life, and simplifying maintenance Enduro ABEC-5 angular contact bearings 73mm BB30A Shimano HTII 24mm Alloy 129g BlackUPC/EAN/GTIN: 811079025142