Original Cane Creek headtube reducer cup to convert IS47 (1 1/4") frames to use an IS41 bearing. If you have an EVO, Synapse, CAAD12, CAAD10, or other 1 1/4" tapered frame and want to use a fork with a 1 1/8" steer tube, this is the best way to do that. This reducer cup is the same size and fit as an IS47 bearing and fits right into the frame. IS41 bearing not included.