1、Effective waterproofness, the separable rubber gasket can withstand the sliding gap, resulting in a gapless movement, preventing dust and moisture from bearing, and has good waterproofness. 2、There is no resistance to lubrication, the separable rubber gasket has the characteristics of double‑side sliding, which will not increase the resistance to the rotation bearing, and the lubrication is high. 3、Groove sealing is strong, and the newly designed end cover greatly improves the sealing performance of the drainage, while reducing the sealing resistance, and the appearance is more high‑end. 4、Aluminum alloy shaft bushing makes the crank power transmission more direct, without plastic elasticity causing power loss and bearing damage, and has better rigidity. 5、Aluminum alloy material has higher metal strength, while maintaining the characteristics of lightness, high strength and light weight of aluminum alloy material. Item Type: Bike BC Bottom Bracket Material: Aluminum Alloy + Nylon Product Size: Length: Approx. 90mm / 3.5in Outer Diameter: Approx. 44mm / 1.7in Inner Diameter: Approx. 24mm / 0.9in Thread Pitch: Approx. 35mm / 1.4in Wheelbase: Used for 68-73mm / 2.7-2.9in Threaded Bottom Bracket Features: Suitable for Use with Bottom Bracket Width of 68-73mm / 2.7-2.9in, Bearing Hollow Shaft, Sealed Bearing, CNC Turning, Anodized. Suitable Models: Mountain Bike / Road Bike / Fixed Gear Bike / Folding Bike 1 x Hollow Bottom Bracket Kit 1 x Bottom Bracket Kit 3 x Washer