This is the praxis works pf30bb30 to shimano bottom bracket adaptor 73mm praxis conversion bottom bracket is designed to be a proper bottom bracket for shimano hollowtech cranks in pf30 and bb30 frames this includes the pf full sleeve which your remove if your frame is bb30 their patent pending design maintains the cartridge bearing outboard of the frame right on shimano spec for greater rigidity and free of frame clip tolerance issues that other systems deal with simply press in the lo