Material: This bike bottom bracket is made of aluminum alloy, ensuring a long lifespan and reliable performance for your bicycle, a versatile addition to your cycling equipmentEnhanced Sealing with Double Silicone: Features double silicone seals that effectively absorb the roundness tolerance of the mounting port at the bottom bracketThreaded System for Optimal Protection: The innovative threaded system enhances frame protection and boosts overall performance, making it an ideal choice for cycling enthusiasts seeking durability and efficiencySealed Bearings for Clean Operation: Equipped with sealed bearings to keep out dirt and water, ensuring smooth operation in various weather conditions while extending the lifespan of your bike componentsCompact Dimensions: With dimensions of 8.65 cmx4.6 cm/3.41 inchx1.81 inch, this bottom bracket is designed to fit seamlessly into your bike setup without adding unnecessary weight Specification: Material: Aluminum Alloy Size Chart: 8.65cmx4.6cm/3.41inchx1.81inch Package Includes: 1 Bike Bottom Bracket Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.