The Kogel T47 External Bottom Bracket is one of the smoothest and most reliable options on the market. Featuring ceramic bearings, this bottom bracket is made to run like new for years on end while enhancing your power transfer. This version is designed to accommodate any SRAM DUB Crankset on a T47 frame with a 68mm shell. A 12-notch bottom bracket tool with a 44mm inner diameter like the Park Tool BBT-79 is all you need to install it. These road seals are designed for low weight and efficiency on road rides. Kogel knows that every pedal stroke is important, and hand makes their bottom brackets to maximize your efficiency.