Features1Metal Frame: This bike bottom bracket is made of aluminum alloy frame, easy to pedal, reduce noise, light weight while maintaining strength. 2Sealed Steel Bearing: Bike BB adopts sealed bearing, keeping the lubricant in the bearings, dustproof and waterproof, suitable for harsh cycling environment 3Anti Loosening: High strength aluminum alloy bike press fit bottom bracket, strengthen the side stability, not easy to loosen, refuse to noise. 4High Strength: This metal bike bottom bracket has high strength and high hardness, not easy to deformation. Press in design can improve rigidity. 5Small And Portable: Aluminum bike BB is light weight, small size, easy to install and use. Suitable for mountain bikes and road bikes for cycling enthusiasts.SpecificationItem Type: Bike Bottom BracketMaterial: Aluminum Alloy, Sealed Bearing, NylonInner Diameter: Approx. 30mm / 1.18inOuter Diameter: Approx. 43mm / 1.69inApplicable Frame Tube Diameter: T47Compatible Frame Five Way Width: 68-73mm / 2.7-2.9inPackage List1 xBikeBottomBracket2 xWashers