1、Aluminum alloy Shell: The outer frame of the bottom bracket is designed for slide cycling and noise reduction. It is light in weight while maintaining strength. 2、Integral Sealed Steel Bearing: The integral sealing constructure retains lubricant in the bearing for good dust and water resistance. It is suitable for harsh riding environments. 3、Lateral Stability: High strength aluminum alloy material can strengthen lateral stability, so that it is not easy to loosen, and will not produce abnormal sound. 4、Accurate Machined: Through accurate machining, the life of this bike bottom bracket is increased and the sealing of the center shaft is improved even more. 5、24mm Inner Diameter: The outer diameter of this bike bottom bracket is 43mm and the inner diameter is 24mm. It is compatible with 24mm cranksets. 1 x Bottom Bracket Item Type: Bottom BracketMaterial: Aluminum alloy, seal bearing, nylonWeight: Approx. 132g/ 4.66ozSize:Inside Diameter: 24mm/ 0.94inOuter Diameter: 43mm/ 1.69inApplicable Frame Pipe Diameter: T47Compatible Frame Bottom Bracket Width: 68-73mm/ 2.68- 2.87in