Wheels Mfg. T47A(asymmetrical) bottom brackets feature thread-together machined aluminum cups and internal Enduro ABEC-3 bearings.For use with 29mm crank spindles. For use in Cervelo, Factor and Felt frames with T47A bottom bracket frame interface. Bearings are easily serviced or replaced. Includes sleeve to fit between cups for added protection from dirt and grime. Machined aluminum cups are durable and lightweight. Item Specifications: Bottom Bracket Shell I.D., 47, BB/Frame Interface, T47, Defined Color, Black, HAVE A QUESTION?Expert customer service by bike experts! A Real Brick And Mortar Retail Bicycle Shop with people you can talk to! Contact Us! (9-5 Mon-Fri, 12-4 Sat & Sun EST) Chat With Us