This is the Praxis Eng. Threaded/BSA M30 BB for installing a Praxis M30 Spindle based crank into a BSA English threaded frame. 68mm Road / 68/73mm MTB / 83mm DH For Praxis M30 spindle cranks being installed on a BSA threaded frame 68mm Road / 68/73mm MTB / 83mm DH 30mm Drive bearing / 28mm NonDrive bearing | cartridge bearings Ceramic version is Grade 5 / ABEC 5 rating Forged & machined heat-treated AL Cups TOOL: Praxis M30 tool required