T47a (asymmetrical) threaded BB cups for T47a frames and 24mm diameter spindle compatible cranks. Cups have internal bearings, and can be used in BB shells with widths from 77.5 - 79mm. Machined aluminum cups thread together directly into a Cervelo, Factor and Felt T47a BB shell. * T47 external cup on the drive side* T47 internal cup on the non-drive side