1、ALUMINUM ALLOY OUTER FRAME: Bottom bracket is made of aluminum alloy frame, slippy pedaling, reduce noise, lightweight while maintaining strength. 2、ENHANCED LATERAL STABILITY: Road bike bottom bracket strengthens lateral stability, not easy to loosen, and refuses to make any noise. 3、DUST AND WATER RESISTANT: Bottom bracket keeps the lubricant in the bearing, good dustproof and waterproof, suitable for harsh riding environment. 4、PRECISE MACHINING: Bicycle bottom bracket is precise machined for long life and has a high strength center shaft with good sealing performance. 5、EASY TO INSTALL AND USE: Cycling bottom brackets are light in weight, small in size and easy to install and use. Great accessory for bicycle lovers. Item Type: Bottom Bracket Material: Aluminum Alloy, Sealed Bearing, Nylon Inner Diameter: Approx. 30mm/1.2in Outer Diameter: Approx. 47mm/1.9in Applicable Frame Tube Diameter: T47 Compatible Frame Five Way Width: Approx. 68-73mm / 2.7-2.9in 1 x Bottom Bracket