Praxis M30 Press Fit bottom brackets are designed to be a proper bottom bracket (BB) for installing Turn M30 spindle based cranks Our patent pending design keeps the cartridge bearings outboard of the frame right on Shimano spec for greater rigidity and free of frame/c-clip tolerance issues that other systems deal with. Simply press in the longer non-drive-cup, then the shorter drive cup threads into it. As the drive cup threads in, our trademark Collet system expands to a precise limit evenly dispersing pressure for a super tight fit. With both cups connected and our collet set exactly to spec, there is no chance the bearings can come out of alignment or wiggle/walk out of the frame. This design also uses a compressible o-ring on the non-drive side cup to compensate for frame shell width discrepancies. For Turn by Praxis or Verve Info cranks only. (not compatible with other 30mm systems) Forged & machined heat-treated 7075 T6 AL Cups Steel cartridge bearings 68mm Road version For BB30, PF30 frames Not for BBRight or BB386EVO frames