Description: This integrated hollow bottom bracket threaded BB made of aluminum alloy outer frame, which is light in weight while maintaining strength, smooth pedaling, noise reduction, and easy installation and maintenance. Suitable for 68-73mm bottom bracket shell. Anodized aluminum alloy, lightweight and durable. Precision machined threads are not easy to loosen, easy installation and operation. The integral seal keeps the lubricant in the bearing, with good dustproof and waterproof effect, suitable for harsh riding environments. Fit for mountain bike, road bike and BMX bike, etc. Specification: Material: Aluminum Alloy Size Chart: Outer diameter: 44mm/1.73inch Inner diameter: 24mm/0.94inch Adaptation: bottom bracket length 68-73mm/2.68-2.87inch Package Includes: 1 Piece Bike Bottom Bracket 1 Piece Conversion Adapter 3 Pieces Spacers Note: Color might be slightly different due to the color calibration of each individual monitor. Please allow slightly measuring deviation due to manual measurement.