This is Praxis' English Threaded M30 BB for installing a Praxis M30 crank into a BSA English threaded frame. For 68mm Road frames and 68/73mm Mountain frames. - Only for Praxis M30 spindle cranks being installed on a BSA/Eng. threaded frame - 68mm Road version / 68/73mm MTB setup - 30mm Drive bearing / 28mm NonDrive bearing | cartridge bearings - Forged & machined heat-treated AL Cups - Praxis M30 BB tool required for installation - Sold separately