Feature: 1. ALUMINUM ALLOY FRAME: Bike bottom bracket adopts aluminum alloy frame, smooth pedaling, reduce noise, light weight while maintaining strength. 2. STABLE AND NOISELESS: The interlocking design of the bike bottom bracket improves rigidity, enhances lateral stability, is not easy to loosen and reduces noise. 3. AIRTIGHT SYSTEM: Accuracy machined BB bottom bracket, increased service life, high strength, better airtight performance, easy maintenance and lubrication. 4. PROFESSIONAL ACCESSORY: Road mountain bike bottom bracket, light weight, small size, easy to install and use, is a great accessory for cycling enthusiasts. 5. DOUBLE O RING: This cycling bottom bracket has double O rings, which effectively prevent water from entering and can be used as a cushion belt for frame and BB. Specification: Item Type: Bike Bottom Bracket Material: Aluminum Alloy Product Size: Approx. 86 x 41mm / 3.39 x 1.61in Suitable for Frame Bottom Bracket Inner Diameter: Approx. 41mm/1.61in Bottom Bracket Width: Approx. 86-92mm / 3.39-3.62in Compatible With 30mm/1.18in Axle Crankset. Package List: 1 x Bike Bottom Bracket Note: Manual measurement, please allow some errors.