In the ever changing world of bottom bracket standards, Praxis aims to have a bottom bracket for pretty much any modern bike and crankset. The Specialized OSBB Conversion Bottom Bracket is suitable for Shimano Hollowtech II cranksets in 68mm Specialized OSBB bottom bracket shells.Compatible with Shimano Hollowtech II cranksets with 24mm spindlesCompatible with 68mm Specialized OSBB bottom bracket shellsHighly durable Enduro bearings are designed to spin freely and last well in harsh conditionsForged & machined aluminium cups are highly durable and easy to fitBuilt around high-quality Enduro steel cartridge bearings and forged and machined aluminium cups, Praxis bottom brackets are built to be strong, durable and not afraid of harsh conditions. The quality sealing keeps grime away from the bearings, while the cups construction mean they can be easily transferred between frames with no fear of damaging them. If you want a dependable bottom bracket that is supremely reliable and easy to install, look no further.