T47/68 Bottom Bracket for Shimano: T47 is a standard created by custom frame builders. It's threaded, has an inner diameter of 47mm, and is 68mm wide. It has the design benefits of being oversized and wide, but also the practical benefits of threads. The cups have CeramicSpeed bearings pressed in. There are two bearing options. The Standard Bearing has CeramicSpeed Balls and hardened-steel races. The Coated Bearing has the same balls running on a 3-micron thick coating placed on top of those hardened-steel races for greater durability and less friction still.This BB is compatible with 68mm frames.Bottom Bracket tool for installation: BBT-69. In The Box:- 2 threaded cups with CeramicSpeed Bearings installed.- 2 dust covers.- Spacer tube.- CeramicSpeed All Round Grease- Sticker Sheet. Installation of T47/68 for Shimano: If you don´t have any experience installing bottom brackets and bearings, we recommend that you have your local bike shop fit your new bearings. Maintenance of CeramicSpeed Bottom Brackets: We recommend that you follow our instructions on how to maintain your CeramicSpeed Bottom Brackets to achieve the lowest friction and the best longevity.